"This update is recommended for Mac mini (late 2012) models. This update addresses an issue that may prevent a USB keyboard from being recognized after the system wakes from sleep."

Late-2012 Mac Mini EFI Update (to fix HDMI Video Flicker) (from Dec 10th, 2012 news page)
(Download page linked. Should also appear in SU on late 2012 mini's but I prefer D/L updaters)

"About Mac mini EFI Firmware Update 1.7 (4.53 MB)
This update addresses HDMI video flicker issues on Mac mini (Late 2012) computers and is recommended for all users.

... When your Mac mini restarts, a gray screen will appear with a status bar to indicate the progress of the update. It will take several minutes for the update to complete. Do not disturb or shut off the power on your Mac mini during this update.

Mac mini EFI will be updated to 0106.03
(I think they mean it will be MM61.0106.B03 (vs previous MM61.0106.B00), but I've not updated yet. (I included EFI/bootrom, SMC, HD4000 rev/drivers, etc in my earlier info below.) Since I've never seen this issue with an HDMI LCD Display or HDMI HDTV on this sample, not sure I will update anytime soon. But also curious if there's anything more than a flicker fix in the later version. (FYI: I did later apply this update.))

System Requirements: Mac mini (Late 2012)"

I didn't see this problem on a sample here, but many owners have reported the problem in Apple's Mac mini forums. (Original thread links below which were only a couple pages long in late Oct, much longer now. And many more threads started on this since then.)
(FYI - it's too early to tell yet as I'm posting just as the update was released, but early reports in the original threads (links below from Oct 29th) showed one user saying his flicker problem is more frequent after the update. Some others were more positive and hopefully remain so. It may not help with the problem reported but I'd try a shut down/restart and try Reset the NVRAM and reset the SMC (AC off). Might also be worth disconnecting/reconnecting/power cycling the display.)
[Later posts there (in several threads) from affected owners noted mixed results - some saying the update helped, others not. One owner with worse flicker after the EFI update said a PRAM reset helped. (That will clear some settings including Startup Disk (see PRAM doc), so check your System prefs afterwards.)]

[Earlier Info/Notes/Tests/Tips follow - Before 10.8.3 & EFI Update 1.7 were released]
(Items below cover sleep/hibernate, USB 3.0 interference, Drive/SSD upgrades, HDTV/HDMI Display tips, EDID & more.)

Another Intel Post on HD4000 Flicker Issue/Fix: (added here Nov. 27, 2012 - comments at Intel later edited)
Per a thread started in Intel's Graphics forum on 2012 Mini HD4000 Flicker, Intel says an update (again) will fix this:

(Update: When I checked on Nov. 29, 2012, the original forum post comments below were no longer there. Nic's post now only says: "For this issue please refer to your OEM for support.")

[What follows below is a copy of the post as it appeared on Nov. 27, 2012]
"We are aware of the flickering issue, and there will be a fix provided in the future. The overall flicker issue is also being addressed here; https://communities.intel.com/thread/32932
(FYI: that's a thread on "Screen Flickering In WMC (Windows Media Center) During Live/Recorded TV", which they say is fixed by a windows driver update.-Mike)

Your OEM (Apple) will provide the driver with the fix when they are done configuring our driver (that has the fix). An ETA on this is currently unknown.
Thank you, Nic"

An earlier Intel forum thread on HD4000 flicker (info below) included a workaround from Intel (run single channel ram) until a bios update (w/fix), but that didn't help most affected mini owners based on their comments.
   As noted earlier here, I have not seen this problem to date, and I've tested/looked for it repeatedly with HDMI to a 2007 Samsung LCD Display, HDMI HDTV direct and via AVR. After the earlier Intel comment about a bios update flicker fix, I listed the Mini's EFI/SMC versions here which some Mini owners with flicker problems replied were the same as theirs. (Although 2 others later said they had earlier an earlier SMC version 2.7f0 vs 2.8f0.) I've also included this (ok so far) Mini's HD4000 revision, graphics file version used, etc. below in case it changes over time.

(Post from Oct. 29th. 2012 follows, there are now -many- more posts/threads at Apple's mini forum on this since then.)
I saw several reports (and growing) in Apple's forums on 2012 Mac Mini Intermittent Loss of Video (HDMI) (flicker, black screens, 'snow' etc) with some cross posts in a thread about short interference (snow) with (Late 2012) Mac Mini HDMI. (Later MANY other threads were also started on the same subjects. Another common complaint was 'washed out' display w/HDMI - notes/tips on that below also.)
   One owner with intermittent HDMI Video dropouts included a copy of his console log with several "display connect changed" and "No display devices are on-line" errors that coincide with these dropouts but not everyone noted/checked for those messages. As always the first suspect is the cable/connection but some reports said same cable was used with other macs, same displays and were fine. (And the usual HDMI suspects are questioned - HDCP, Handshaking, rates, etc.)

Speaking of HDCP, some older monitors/TVs are not HDCP compliant. But some Mini owners have had HDCP issues even with monitors/TVs that support HDCP and played HD content fine with other Macs/computers. A Late 2012 Mini owner had reported he was unable to play VUDU HD or HDX because of HDCP issues, despite the display (model not mentioned) being HDCP compliant he said. (Later found this Vudu Support Note on HDCP, HDX/HD Playback with Mac external displays.)
   Here's some Apple forum threads on HDCP issues - "mac mini 2011 hdcp issue" (later post includes 2012 mini owner on Vudu HD/HDCP problems) and an even older thread (started in 2009) on HDCP Authorized display issue with Mac Mini which has some of the usual rants on HDCP (and Apple).
  FYI on new Apple HDCP Doc: On January 30th, 2013 Apple posted a new support doc About High Definition Copyright Protection (HDCP) and Apple products (no longer online) that included info on on HDCP Key (connected/supported device) limits. (Unless that system is buggy, I doubt most users will exceed the listed limits.)

BTW: Although I avoid 'hot swapping' HDMI connections personally, a Troubleshooting tip in Apple's Mac Mini HDMI FAQ (now reverts to Connect to HDMI from your Mac) for an HDTV not recognized by the Mini suggests "Leave your Mac mini turned on while you power off the HDTV. Unplug the HDMI cable from the Mac mini and plug it in again. Power on the HDTV".

Some replies in November noted getting their mini replaced for the HDMI/Display flicker/dropout problem and Apple is investigating. I saw one report where a swap didn't help, one that said it did (so far at least). Later several others said they exchanged their Minis but problem persisted. (This was before the EFI 1.7 firmware update was released.)

(Sept. 25th, 2012) Intel Forum Thread Post on HD4000 Flickering Fix: (started mid-June 2012)
An Intel Forum thread started in mid-June 2012 titled Intel HD 4000 Graphics occasional flicker (link no longer goes to thread) that suggested removing all but one ram module (running single channel) until you can update the motherboard bios with a fix. Here's a reply from Robert U. (Intel) on Sept. 25, 2012 (post #107):

"[Correct Answer] Re: Intel HD 4000 Graphics (i7-3770K) occasional flicker
This issue is a BIOS issue specifically with the Memory Reference Code (MRC) version 1.4.0.0 or older. Please contact your system or motherboard manufacturer for a system BIOS update for your system or motherboard that includes MRC 1.5.0.0 or newer.

If you have a system with 2 or more memory modules and are comfortable with removing all but one of them so that your memory is in single channel mode, try and remove all but one of them and the issue will go away. This can be used as a workaround until you are able to update your system BIOS from your system or motherboard manufacturer that includes MRC 1.5.0.0 or newer."

Even as a temporary workaround, running only 1 dimm isn't going to be acceptable for many. (And as of Early Nov. 2012, I've only seen 1 affected Mini owner that thought running 1 dimm helped - many more said it didn't. Knock on wood, I haven't seen the HDMI problem yet with this mini server (6,2) model (w/SSD boot drive swap), but then my config isn't typical either (see notes below).)

I checked the EFI/Bootrom (and SMC) revs of the 2012 Mini I used (2.3GHz core i7 (mobile), 2x2GB ram - no flicker/dropout issues seen so far) and it is:

This Mini (6,2) EFI/SMC versions: (as shipped in Oct. 2012)
• Bootrom (EFI): MM61.0106.B00   (.B03 after EFI update 1.7)
• SMC: 2.8f0

Since I'd not seen any flicker (to date) I wondered if this could be a factor but early replies from owners with dropout/flicker problems said their minis had the same versions. (Update: I saw 2 late Nov. 2012 posts in the longest apple thread on this problem that said they had SMC v2.7f0. I posted my EFI/SMC versions here on Nov. 2, 2012 (after adding the Intel post (above) on a bios update/fix) but didn't get any reply here, so on Nov. 5th, asked in the apple thread for EFI/SMC versions from mini owners with the dropout/flicker problem to see if mine (above) were different. Early replies on that page (page #4) of the thread back then (Nov 6th replies from "koyeung", "chrunck", and "ph47") noted the same versions I have above, including SMC 2.8f0. Didn't say if they had a Mini 6,1 or Mini 6,2 (server) model in case that's a factor in SMC version differences.)

And here's the Intel HD4000 Info (ID/revision) which should be common also (but rev might change over time for later steppings/builds). I've also included the versions of some related software files. (Again from a Server model w/10.8.2 build 12C2034.)

Intel HD4000 Info:
• Device ID: 0x0166
• Revision ID: 0x0009
  
  Software (OS X 10.8.2, build 12C2034**):
• AppleHD4000Graphics - 8.6.22
• AppleGraphicsControl - 3.2.13
• AppleGraphicsPowerManagement - 100.12.81

If anyone is curious about any other info (or has a newer version in their Mini) let me know. Thanks.
(** No change to versions after reinstalling the later build (12C3104) in Nov. 29th's reposted 10.8.2 updater)

"Washed-Out" Displays (wrong mode/gamma/clipping): (Update: OS X 10.8.3 rel'd 3/14/2013 improved 3rd party display color/PQ per posts in previous mini forum threads. Info below is from Oct/Nov 2012.)
There's also been more threads started on various display quality (washed out/gamma incorrect) problems, some (see example images 4th post down) appeared to be cases of wrong gamma/blown out contrast/white clipping. (I also saw this before creating a custom profile and monitor adjustments - image on Samsung LCD monitor was almost totally washed out.) Similar complaints were reported by 2012 MacBook Air owners (also HD4000 graphics) using HDMI displays. Universal Access contrast setting wasn't the cause. (I wondered if the Mini's output was typical RGB or YCbCr. YCbCr is typical output from HDMI Blu-Ray players for instance, although many have options to change that to RGB. Also see below for info on EDID/Mods for Macs to force RGB mode, which may help with some displays.)
   I remember washed out displays/custom profiles (gamma) required even with my old G5 tower using a DVI 24in Dell LCD many years ago, but some of these recent examples seem worse. (Like wrong gamut/mode.) (BTW: There's also a past thread at Intel's forums on HD4000 black levels/RGB ranges and an earlier thread (originally on HD3000) Intel HD graphics not outputting full range RGB via HDMI.)

Some Samsung LCD owners with input naming options said renaming the Input (selecting a source mode I suspect) to "PC" or "DVI PC" helped. Or see if the Monitor has an "PC" (vs "TV") input option. (Some monitors may have that option - my older 2493hm model doesn't.)
   Regardless of LCD monitor model, I'd also check the display's built-in menu/options for gamma, brightness, contrast and color - and I'd disable any 'dynamic' contrast/color modes. (Especially before calibrating/creating a new colorsync profile.) Despite having some adjustments in the Samsung 2493hm menu's for all that (including 3 gamma options), nothing at the monitor end really solved it until creating a custom display profile for it on the Mini. (But it's a cheap TN panel and not in the better class of LCDs.)

While at the Samsung site to get a PDF for my old 2493hm, I noticed they had a firmware update notice (since April 2012) for SA Series LED Monitors that lists improved compatibilty and PQ.
(That note with link was even at the top of my old CCFL 2493hm model page)

"SA Series LED Monitor Quality Improvement Announcement April 4, 2012.
Samsung has released a firmware update for Samsung SA series LED Monitors. This firmware update is for improved performance (better picture quality and PC compatibility).
If you have one of these models, Samsung recommends that you download and install the latest firmware update specifically designed for your monitor."

This may not be news to all SA display owners (and some may already have updated firmware) but posting anyway just in case. (The download is a PC exe.)

Monitor and HDTV Tips for Best Sharpness:
Usually the best setting and sharpest text is a 1:1 mode on the HDTV - not the typical default 16:9 aspect ratio used for TV/tuner mode which also has overscan. You do not want Overscan Enabled, you want a 1:1 pixel map. [Some HDTVs may call the 1:1 mode option "Just scan" (LG) or "Screen Fit" (Samsung).] If OS X thinks your Display is a TV, disable Overscan in OS X prefs. If the Display/TV has the option - try setting it to PC mode. If you've not already read it, see Apple's Mac mini (early 2006 and later): Connecting to a TV (no longer online) and Apple's article: Fix overscan or underscan on your TV or projector. (There's other Mac Video/HDMI/Audio info/tips on our Mac Basics/Info/FAQ's page.)
   As far as colorsync profiles, IF you have an IPS panel based HDTV - try using Apple's 'LED Cinema Display' colorsync profile. It defaulted to that profile with the LG 7600 (IPS panel) connected, but if that profile does not appear in the listing, make sure "show profiles for this display only" is unchecked. (It looked very good on an IPS panel LG HDTV I tested, but of course won't on all panels.) Some TVs may also have a Color Gamut (or color space) adjustment option, but you may not be able to change that with some connections and some TVs. (Some may not even have the option.) Also see the info on EDID/mods that follows.

EDID (Extended Display Identification Data) Mods/Info:
(Some also use EDID mods to force RGB mode if Mac external video is using YCbCr (typical for TVs) and the monitor works best with RGB.)

Here's a thread from November 28th, 2012 on (2012) Mac Mini HDMI Output Problem w/LG L246WP that has notes on EDID mods. (I had no issues w/2012 Mini HDMI to LG 55LM7600 HDTV.)

BTW: A 2010 Mini owner with a Samsung TV (unspecified) that had EDID issues said he used an Gefen HDMI Detective Plus (2012 Gefen product page link with manual, specs, etc.) to solve it.

"(post from zGoats down the page in this thread)
If this does turn out to be an EDID issue, an HDMI Detective could be used to circumvent the issue. I had EDID issues with my 2010 Mac Mini and a Samsung TV and the guy linked below worked.
www.amazon.com/Gefen-EXT-HDMI-EDIDP-HDmi-Detective-Plus/dp/B001RIMZUW/"
(AZ page for Gefen HDMI Detective Plus)

Read the customer reviews there. (And the docs/info at the Gefen page above.)
FYI: A 2012 Mac Mini owner reported he had to keep the HDMI Detective's power supply connected when used with his 2012 Mini. (Not true with his 2011/2010 minis.) Gefen notes normally you only need the PSU connected for initial setup however they mentioned in some cases there may be insufficient power, requiring the PSU to be always connected.

Force RGB Mode (EDID patch) Script: (Feb 2, 2013)
Here's another/more recent thread on EDID mods/forcing RGB mode for external displays with Macs that includes an EDID patch script - see Dell U2713H on Mac: forcing RGB mode instead of YCbCr. Down the thread is an update with universal EDID patch script. (I've not used this personally.)

My Experience with Late-2012 Mac Mini HDMI Video: (from Oct. 29th, 2012 updated in Nov.)
   I used a late 2012 Mac Mini (2.3GHz i7, 4GB (2x2GB) RAM, (SATA2) Toshiba 512GB SSD (DIY swap)/1TB HD. Late 2012 Mac specific OS X 10.8.2 update build applied from D/L, not software update) for several hours a day over a 2 day period connected via HDMI (no adapter) to an old Samsung 2493hm 24in LCD monitor (1920x1200, CCFL backlight, budget TN panel) I had since late 2007 IIRC. (I'd not used that monitor in so long I'd forgotten it had built-in speakers. HDMI from mini also supports audio.) No video dropouts or glitches were seen during that time. (I will post if a dropout is seen later.)
   I disabled system and display sleep, although the screensaver (default w/black background) kicked in a couple times after I'd left the system idle for awhile. No display/HDMI issues seen with that or after waking from sleep. (But see below - if left in sleep for hours, the new mini hibernates/powers off, despite PMSET having hibernate disabled.)

2012 Mini goes into Hibernate/Powers Off after hours of Sleep:
   BTW: I've not messed with the PMSET defaults (which has hibernate off but also has settings for autopoweroffdelay, standby and standbydelay) but if you leave the late 2012 Mac Mini in sleep for more than a few hours (>4?) it will hibernate/turn off. (Later I saw an apple forum thread on that - Mini hibernates despite pmset saying it shouldn't that discusses changing PMSET options.
I disabled autopoweroff and standby (using terminal - "sudo pmset autopoweroff 0" and "sudo pmset standby 0") which seems to help - it woke ok after 4 1/4 hours of sleep. (Verify settings with "PMSET -G".)
[Update/Info on 2012 mini/iMac Hibernate: Here's an Apple doc (updated 2/28/2013) titled Mac computers: Progress bar appears after waking from sleep (no longer online) that explains why newer Macs (including the late 2012 mini and iMac) go into hibernate basically after hours of sleep, even when connected to AC power. Per Apple, this was added in OS X 10.8.2 suppl. update 2.0 to comply with European Energy Standards (ErP Lot6).]

FYI on sleepimage file:
If your Mac goes into hibernate and you don't plan let that happen again (i.e. with desktop macs) you can save Gigabytes of disk space (especially important for SSD users) by removing the "sleepimage" file written when the mac hiberates. (This was covered years ago here in a 2009 post on Tips for OS X SSD Users.) The sleepimage file is found in the /var/vm/ folder. Using the Terminal, simply cd to that directory and sudo rm that file. (Sleepimage file size varies depending on amount of installed RAM.)

Although no video dropouts seen (so far), when connected to the Mini (HDMI) the Samsung LCD did have an extremely washed out image. (blown out contrast/wrong gamma/clipping - a custom profile cal in OS X on the 2012 Mini thought the 2493m had a native gamma of appx 1.5!) After using display prefs color (expert) option to create/calibrate a colorsync profile, the Samsung looked a LOT better than using the default HD709 profile. But again it's a low-cost LCD (TN) and can't match the PQ of better/more expensive displays. (Many years ago I used a great shareware colorsync/display calibration utility called SuperCal (bergdesign.com), but didn't have it handy. SuperCal v1.2.2 is listed as OS X Mountain Lion/Gatekeeper compatible.) [I later was able to use SuperCal 1.2.2 (unregistered) on the Mini w/OS X 10.8.2.]

BTW: Apple's Mac Mini (2010 and later) FAQ about HDMI (no longer online Oct. 24th, 2012 revision date noted:

"The HDMI port supports up to 1080p on HDMI connections. With the HDMI to DVI adapter, the HDMI port will work with resolutions up to 1920 x 1200."

Despite that note (1080P = 1920x1080), based on what I've seen with a Late 2012 Mini, its HDMI can do 1920x1200 with a direct HDMI-HDMI connection. If the 1080P limit was true (1080P Max via HDMI-HDMI) then on a 1920x1200 LCD connected via HDMI, there would either be some vertical scaling (for 1080->1200) or if 1:1 mode, some slight black bars. (For LCDs, 1:1 pixel mapping is the sharpest mode.)
  With a Late-2012 Mini connected (HDMI-HDMI) to my 1920x1200 Samsung 2493hm and OS X's Display Prefs set to "Best for Display" the display/text did not look scaled/soft and using the Samsung's menu it reported a 60Hz, 1920x1200 signal (74.2KHz IIRC). Selecting the "Scaled" option in OS X also showed that 1920x1200 was an available resolution.
  Although I was able to run at 1920x1200 without any problems (so far at least), that note in the Apple Mini HDMI FAQ made me wonder - for anyone with the HDMI flicker problem, does it matter if you set HDMI display resolution to 1080P (1920x1080) or lower? (For those with the problem, It may not matter - just curious if a lower display rate (rez) has any affect for them. And some have reported flicker/dropout problems even with HDMI to DVI adapters.)
(That Mac Mini HDMI FAQ doc now has a Nov. 23, 2012 rev date and still notes up to 1080P for HDMI-HDMI.)

Will test the mini later with HDMI-DVI adapter to 2493hm LCD, a MDP Cinema & (HDMI) HDTV.

Updates on What I've Seen/Checked:

• Late-2012 Mini's Thunderbolt to (Mini DisplayPort) 27in LED Cinema Display:
     Used a 27in MDP Cinema Display for about a week with no problems seen. (Using default LED Cinema display profile of course.) Looks great and has nice audio for a monitor too.
  (Although rare compared to all the complaints on HDMI video flicker/dropouts, there have been some MDP/TBolt video flicker reports, although some said using TB/MDP was their workaround.)

• Late-2012 Mini's HDMI to LG LM7600 LCD (LED backlight) HDTV:
     On Saturday (Nov 10th) I had a chance to use it for about 5 hrs with an (IPS panel) LG 55LM7600 (HDMI-HDMI, no AVR, HDMI control not enabled) and didn't see any video dropouts. First played 2 episodes (1 disc) of HBO's "Band of Brothers" series on DVD using a USB Apple Superdrive. I did see an audio issue once - stutter/loss of audio when starting the 2nd episode. Not repeatable and no loss of video. (The USB superdrive may have spun down as I left on menu for awhile (BR break) after the 1st episode finished.)
     Another few hours of use after that without any issues. (Played EyeTV recordings (exported to QT) of OTA (antenna) TV shows SNL (1080i) and the final American Lemans race (720p).) Very nice PQ on that TV and no video dropouts seen the entire time. So many owners have reported HDMI dropouts/flicker that I'm surprised I haven't so far with this Mini 6,2 sample from late October.) [I haven't tried it with my 2008 (CCFL) Philips LCD HDTV.]
  
  FYI: I set the LG's Aspect Ratio option to "Just Scan", not 16:9 (that's used for TV with overscan). I used the standard "LED Cinema Display" Colorsync profile with the LG LM7600 HDTV (both are IPS LCDs) and it looked great (color, hue, saturation, sharpness, gamma, contrast, gradients, skin tones, etc). I prefer LCD displays over plasma, but I'm not a "torch mode", "vivid"/over-saturated colors fan.
     TV was previously calibrated using the WoW (blu-ray) disc. (Not as good as a Pro calibration of course, but looked great.) PQ on that 7600 sample was very good, better than average I think. (Tack sharp, wide viewing angle, better than expected black levels for an IPS panel, no banding, good uniformity for an edge-lit, no noticeable 'flashlighting', DSE or clouding.)
  
  
• Late-2012 Mini HDMI through AVR (Yamaha A2000) to LG HDTV:
  (Mini HDMI to AVR input, AVR HDMI out to TV.) Only tested a few hours (including 4 episodes of "Worst Week" DVD playback), but no issues seen. A2000 video processing was off, although it still does AVR volume bar overlay on TV. Used same TV settings as with direct connect - Aspect Ratio "Just Scan", LED Cinema Display Color Profile used in OS X. (HDMI control was not enabled on the HDTV or AVR. Some devices may refer to HDMI control as CEC, SimpLink, Viera Link (Panasonic), or similar names.)

I've known about the HDMI video flicker/dropout problem since the beginning and have always watched for it because of the many reports from other owners. During the above tests of course I tried to keep an eye on the screen constantly with minimal interruptions (including lots of Movie/Video playback with max concentration/focus on the screen) but of course nobody can spend 100% of the time all day focused only on the display.
   Some affected owners have said they saw the problem almost once an hour, others rarely (once a day or so). Some have said they noticed the problem the first day (again) with replacement / exchanged systems. I would think by now I'd have seen something but I watch for it closely with every use. However the mini is not the primary work machine.

Since I've not noticed any HDMI video problems on this sample (yet at least) and the fact it's not exactly typical, here are some specifics/notes about its setup/config:

• Mac Mini 6,2 (server model - single drive models are 6,1)
• 2.3GHz Quad-Core i7 (mobile)
• Bootrom (EFI): 61.0106.B00, SMC: 2.8f0 (noted earlier under Intel's post on HD4000 flicker)
• Intel HD4000 Revision ID: 0x0009 (noted above also, including some driver file versions)
• OEM 2x2GB RAM (also tested w/2x8GB for 2 days*)
• OEM 1TB 5400rpm HD (2nd internal drive)
• USB Apple (alum) Keyboard and Mouse
• System/display sleep disabled
• No 3rd-party addons installed
• No iCloud/sync (will not be used)
• Bluetooth off, WiFi enabled (for now, will use Ethernet later. BTW: this mini's WiFi range seems poor.)
• Time Machine off (TM backups will be done manually to internal 1TB HD when desired)
• iTunes not used (won't ever be for this machine's end use, although DVD player was used for tests above with USB Apple Superdrive)
• This Mini shipped w/OS X 10.8.1. I updated using download of Late-2012 Mac's OS X 10.8.2 build (Oct. 24th release, build 12C2034), installed at first boot - already had it on thumb drive. I later installed the Nov. 20th, 2012 release of OS X 10.8.2 Suppl. Update 2.0. (FYI: As noted below, on Nov. 29th I installed the later build 12C3104 (Nov. 29th release) over build 12C2034.)

* A pair of 8GB Sodimms (16GB total) was also used over the weekend during the tests with HDTV and AVR above - no problems were seen. (BTW: With 16GB of RAM installed, the Intel HD4000 vram was shown as 768MB in OS X. Bootcamp/Windows users reported 1,686MB vram listed with 16GB RAM installed in their Mini.)

The 512GB Toshiba SSD was chosen due to price/capacity (512GB, <50 cents/GB) and its performance is more than good enough (appx 220MB/sec reads, 170MB/sec writes) for this machine. (Using the Mini w/SSD boot drive for awhile makes going back to the old work iMac (w/platter HD) feel like slow-motion/molasses. Another reminder of how big a boost an SSD can make, especially compared to notebook platter drives the mini uses.)
  Even though a faster SATA 3 SSD might benchmark at twice the speeds of this one, I really didn't need (and can't justify) anything faster/more expensive for this mini (that will be a file server so sustained rates will be network bound really). Since 99% of the end use will be reads, hopefully the SSD lasts longer than the OEM notebook platter HD spinning 24/7 (as well as having much better random access). And being an SSD model that Apple used in the past, it may (hopefully) be more reliable than some others. But I know that's a roll of the dice with anything.)
[SSD Update: In March 2013, I swapped the (SATA2) Toshiba SSD for an Intel 520 SSD (SATA3).]

Newer Minis ship w/10.8.2: (at some point they will ship w/later versions of course)
As of mid-November 2012 some later production Minis shipped with OS X 10.8.2 installed. (Initial reports said the same build 12C2034 from Oct. 24th updater that was pulled, but that may change now that a later build was released on Nov. 29th)
On Nov. 20th, Apple released an OS X 10.8.2 Supplemental Update 2.0 with Keychain fixes (fix repeated prompts for keychain access, problems ejecting Discs, authentication problems in Mail/Safari, can't send/recv with Messages app) that I think was to fix problems seen after the (later pulled) "Mid-2012 MacBook Pro/Air Update 2.0" although it also appeared on this Mini with the late-2012 OS X 10.8.2 (Build 12C2034) I'd applied earlier (before that update was pulled). I had not seen problems like that but installed Supplemental Update 2.0 from a download updater (after a backup) in case there was some keychain issues that I'd just not seen yet. (Suppl. Update 2.0 did not change the 10.8.2 build number.)

OS X 10.8.2 (or later) Mini (Dual Drive) SSD Upgrade Note: The (2 HD) Mini I'm using (bought late Oct. 2012) shipped with OS X 10.8.1 (boot volume and restore partition) and I swapped in an SSD (removing 1 of the HDs) before I updated to OS X 10.8.2. However as of mid-November, Minis ship with OS X 10.8.2 pre-installed and anyone that swaps in an SSD as a 2nd drive (w/HD in other bay) may have Disk Utility in the Recovery Partition think they have a 'damaged' "Fusion Drive" setup. (Volume names appear in red.) Any DU 'repair' will erase the drive(s) to create a Fusion volume. On Nov. 20th, 2012 OWC posted a blog about this with more details: Special Note on Adding SSD as 2nd Drive in 2012 Mac mini that shipped w/OS X 10.8.2.

(Nov 29th, 2012) Late-2012 Mac's OS X 10.8.2 Update Reposted:
On Nov. 29th, 2012 Apple reposted the 10.8.2 update for late-2012 macs that was pulled earlier this month (appx Nov 17th). The same URL/same page date, description, same file size (listed on DL page) etc. as the original release on Oct. 24th but a with a slightly larger (less than 1MB) D/L file size than Oct. 24's D/L I had saved.
   I decided to see if the (Nov. 29th) newer build OS X 10.8.2 D/L updater would reinstall over the Late-2012 Mini's 10.8.2 build 12C2034 (which also had the OS X 10.8.2 Suppl. Update 2.0 installed) - it did. I rebooted and checked the OS X Build number - it's 12C3104.
   I also checked to see if there were any changes in some HD4000/graphics related files I'd listed earlier (w/build 12C2034) - no changes in their reported version numbers after installing build 12C3104.

Late 2012 Mac Mini CineBench 11.5 Scores: (updated for OS X 10.8.3 scores)
I ran Cinebench v11.529 on the Late-2012 Mini (2.3GHz Quad-Core i7) while it had 16GB RAM installed (HD4000 reported as 768MB). Connected via HDMI to the (1920x1200) Samsung 2493hm LCD Monitor (looking much better using calibrated display profile to correct gamma/washed-out display with the default HD709).
(Saw a nice OpenGL score boost with OS X 10.8.3 on this Mini. 10.8.3 test ran on MDP 27in Cinema LCD.)

OS X 10.8.2
• OpenGL: 22.85
• CPU: 6.22
  
  OS X 10.8.3
• OpenGL: 26.51
• CPU: 6.24

No HDMI flicker/dropouts, etc. seen during repeated CB runs and hour long runs of the OS X "Shell" (kaleidoscope like) screensaver, DVD (disc) movie playback, short game of Tomb Raider Underworld. Also tried Call of Duty 4 (at 16x9 rez). (Mini wasn't bought for gaming, but just something I had around to try during tests for HDMI flicker/video loss.)

If I see any HDMI video flicker/dropouts in the future I'll update this page to note that.
(From some reports, I've wondered if a system/prefs file is getting corrupted and perhaps my (SATA2) boot drive is immune.) As of late November, Apple has not issued a statement on this and 2012 Minis are still available at the Apple store. But despite many reports of returned 2012 Minis in the last month for the video flicker/dropout issue, I've seen no refurbished 2012 minis listed at the US Apple online store. Not checked their ebay refurb store however.
[Update: On Dec 10th, 2012 Apple posted an EFI Firmware Update to fix HDMI flicker.]

(FYI: A thread on HDMI display issues after 10.8.2 in the MacBook Pro forum suggests deleting some windowserver plist files. Also see post from "JevGenius" in page 8 on displays2 plist.)
   Also another interesting thread is one started in April 2012 on Color output format via HDMI/MDP where some indicated the video output format is not (typical PC) RGB/sRGB but YPbPr (?). (I associated YPbPr with analog/component video, vs YCbCr with Digital/HDMI video from a blu-ray player for instance. I originally thought the Mini's HDMI output might be YCbCr vs RGB.)
   [There's also a recent thread titled Force RGB Color Space over HDMI? that has some some notes on DVI adapter workarounds and that output is RGB when running bootcamp/Windows.]

BTW: I had noticed the Apple's 2012 Mac Mini Tech Specs page didn't include HDMI under "Video support" and only listed ThunderBolt and available Mini DisplayPort adapters (DVI, VGA, etc.). HDMI is listed in the "Audio" and "Connections and Expansion" of course and also on the Mini's Features page with the tag "No screen is too big" under the "HDMI" heading. (Just found it odd they don't include HDMI in the specs page "Video Support" listing but maybe just an omission/carry-over from an older pre-HDMI mini page.)

USB 3.0 and Bluetooth/2.4GHz WiFi Interference: (Dec. 1st, 2012)
As I mentioned earlier (above), I don't use Bluetooth (it's turned off) but I've seen some complaints about poor Bluetooth performance with 2012 Mac Minis that used USB 3.0 hard drives. (This Interference could also affect 2.4GHz WiFi.) I noticed this paragraph (bottom of page) on the subject in an Apple article on Using USB 3 devices on Mac computers FAQ (in 2012, article now no longer online), although from the wording it seems targeted to USB 3.0 Mac Notebooks, but that may be because it was written before USB 3.0 Mac desktops like the Late-2012 Mac Mini were available:

(Clip from Apple Support doc linked above)
"I sometimes have difficulty with Wi-Fi or Bluetooth devices when USB 3 devices are attached to my computer. What could be wrong?
Some USB 3 devices, hard drives in particular, can generate radio frequency interference that can cause Wi-Fi and Bluetooth devices operating in the 2.4GHz band to have issues communicating with your computer. Do not place hard drives or other USB devices behind the rear of your Mac near at the hinge of your screen. The antennas for Wi-Fi and Bluetooth are located there, and USB 3 devices placed there may interfere with your wireless connections. See this white paper (PDF) for more information."
(The white paper link www.usb.org/developers/whitepapers/327216.pdf is no longer there.)

The linked white paper (PDF at usb.org) was from Intel, titled USB 3.0 RF Interference Impact on 2.4GHz Wireless Devices and was well worth a read.

(Update) 2012 Mac Mini DIY Bluetooth Module Shielding Mod: (Dec 6th, 2012)
OWC posted a Late-2012 Mini BT module DIY shielding video in their blog saying their tests showed it helped mitigate this issue.

   I don't have a Firewire Audio interface to test this but a later post in OWC's blog from 'mus0r' (using an Apogee Duet Firewire Audio Interface) mentions hearing some audio noise in his speakers during mouse movements. The post didn't note info on mouse used (Bluetooth or wired/USB) but here's a later reply from the author:

"This was me. To answer your question, the mouse in question was a Razer Naga USB mouse. I switch to my Razer Death Adder (also USB) and found that the noise was less, but still present. No resolution for me so far."

Apple Article on USB 3.0 Devices affecting Bluetooth Performance: (Jan. 31st, 2013)
Apple posted a new support article on 1/31/2013 about Bluetooth: Unreliable wireless performance may occur when USB 3.0 external devices are close which included some common sense suggestions like moving the USB 3 device, using better shielded USB 3.0 cables, etc. (That link now goes to Resolve Wi-Fi and Bluetooth issues caused by wireless interference.)
   (BTW: In January 2013 original article on USB 3.0 external devices, the Macs listed included a Mac Pro (as of Jan. 2013 article date, no Mac Pro existed with onboard USB3 yet) but not the Late 2012 iMac which does have USB 3.0. (If the iMac was not omitted by mistake, then maybe its design is better shielded.)