I did not remove the foil tape over the board to see if there's a way to remove the base board from the drive to swap it out for an SATA one, but it looks like its soldered/riveted on.
(BTW - A reader replied to this post saying the 500GB Passport models are also this way.)
The 1TB model included 256-bit hardware encryption support (unlock app included in the 'virtual CD' that mounts every time with the HD) as well as backup software (which I'd be leery of installing personally).
I wish the drive had a faster interface (not just USB2) such as eSATA or FW. (As usual with USB2, performance was disappointing - at best appx 30MB/sec xfer rates based on a quick benchmark run.)
I foolishly thought (as was the case with older/early models) that this was a way to get a much lower price on the 1TB WD (12.5mm high) notebook drive (the old '2 for 1 upgrade - reusing the original notebook HD in the ext case), but don't make the same mistake I did.
I also saw portable (USB) Toshiba 640GB drives and 750GB Seagate's but not sure if they are adapted SATA models or not. (I didn't even see a 750GB momentus listed at Seagate's site yet - I do remember the Toshiba 640GB (9.5mm high IIRC) drives being announced awhile back.)
Update/FYI: I managed to trade the WD 1TB for a Toshiba 640GB USB drive - my gut feeling was it had a std SATA HD inside (the 9.5mm high/2 platter HD). That case was easy to take apart (just run a fingernail all around the top lid to release the many tabs). Drive inside was SATA (w/USB adapter board) - a 5400rpm Toshiba MK6459GSX.
I had a reader say the Seagate 750GB USB portable also had a std SATA drive. The Seagate 750GB's USB case did have the USB port on the side, which made me think it's also an adapter board slid on a std SATA HD. But I decided to go with the ($40 cheaper) Toshiba.

"About Logic Pro 9.0.2
This update improves overall stability and provides numerous fixes and enhancements. Issues addressed include:

• Flex Markers can align & snap to MIDI notes
• Performing a punch-in recording with Replace Mode now behaves correctly
• The I/O plug-in adds an option for latency measurement
• TDM plug-ins now behave as expected. (Only affects users with Pro Tools HD audio hardware.)

The update is recommended for all users of Logic Pro 9.
For detailed information on this update, please visit this website: Logic Pro Release Notes"

"SiI 3132 Mac OS X 10.6 & 10.6.1 BASE (non-RAID) BETA v1.1.11 (10.8.2009)
Use this BASE (non-RAID) driver with Mac OS X 10.6 and 10.6.1 for Mac Pro and MacBook Pro. Please contact the external enclosure or hard disk drive manufacturer for problems specific to the device."

The top of the page also has a FYI ("Support policy & intended audience") about SI not supporting end-users directly, etc.
BTW - Tuesday morning a reader sent a note that Sonnet also released 1.1.11u drivers for their 3132 based PCIe and Expresscards. (As before I suspect the pkg contains the same SI driver.) However Sonnet notes that 1.1.11 also fixes the >2GB ram problem some had seen in the past. (I didn't see that problem with 1.1.9 personally.)
(Update/Reader Feedback on these drivers: See Tuesday's news for several reader reports on these drivers w/OS X 10.6.1 from MacBook Pro/Expresscard and Mac Pro/PCIe SATA card users.)

Firmtek already posted Snow Leopard drivers (w/64bit support) for their 3132 based PCIe and Expresscard, but they're tied to the Firmtek brand scards. (There were many 3132 based cards sold under dozens of 'brands.)

As mentioned the day Snow Leopard was released (actually the day before), The OS X 10.6 installer removes any 3132 drivers present during the install/upgrade (any version, not just the 1.5.16.0 (RAID IIRC) driver listed in the original apple doc on OS X v10.6 incompatible software), although reinstalling v1.1.9 (non-RAID) drivers seemed to work for many of us (ref: previous posts here since Aug. 28, including some tests I did with a 3132 based expresscard and PCIe card).
I removed the 1.1.9 drivers from the MBP after getting the natively supported JMB360 eSATA card but still have 1.1.9 (32bit only) installed on a Mac Pro with the ($19.99) Dynex PCIe card.
This morning I did install the 1.1.11u Beta under 10.6.1 on that Mac Pro to see if the beta had 64-bit support. Booted w/default 32-bit kernel (driver loaded) and 64-bit kernel (no driver loaded). It mounted an HD in a Voyager Q dock with a (default) 32-bit 10.6.1 boot but not exercised the drive/connection yet although I did run a DU verify on it. (As before, the mounted drive is seen/reported as SCSI with the 3132 card/drivers - with the natively supported JMB360 expresscard connected drives (in TT eSATA/USB HD dock) are reported as SATA.)
BTW - also got a short mail from another reader this AM that he's using these drivers with his Mac Pro and Addonics 3132-based PCIe card.