"About (Late 2013) Mac Pro SMC Firmware Update 2.0 (544KB)
Recommended for all Mac Pro (Late 2013) models.
This update enables Mac Pro to enter Power Nap without running the fan for most Power Nap activities, and addresses a rare issue where a low-speed USB device may not be detected at boot."
Per the updated page of Intel-Based Mac Firmware Updates (below), this is 2.20f18.
(BTW: One Mac Pro owner said his (new alum.) USB keyboard was not recognized after the update (an older USB keyboard was), but zapping the PRAM helped. (Sometimes just disconnecting & reconnecting devices after an update helps so I wonder if just swapping the alum keyboard back would have also worked.) Another old tip for problems after an update (like high fan speeds or other power related issues) is to reset the SMC.)
The Xcode Update for OS X Server (Mavericks) addresses an issue that could interrupt bot integration on headless servers running OS X Mavericks v10.9.2.
The Xcode Update for OS X Server (Mavericks) is available both as an automatic software update from the Mac App Store, and as a manual download from the Apple Support website. (not there yet as of post time)
If you are using the Xcode service in OS X Server (Mavericks), install the following updates on the server:
The OS X Mavericks v10.9.2 update
The Xcode Update for OS X Server
The Server v3.0.3 update
(Added a note about the upgrade order to yesterday's post on OS X server v3.0.3.)