As of the 11/20/2012 update for the 32-bit version and the 11/17/2012 update for the 64-bit version, the following are known issues of which to be aware:
At the partitioning stage of the ubiquity installer, please take special note of where you want grub2 to be installed. Most users will want it to be installed to the MBR of /dev/sda (the first and usually only hard drive in a system but it likely will not default to that.) This is upstream bug https://bugs.launchpad.net/ubuntu/+source/ubiquity/+bug/1067966
Once rebooting into the installed system it may take 30 - 90 seconds from LightDM / gtkgreeter to the usable desktop with panels. This issue is under investigation. Once the desktop does start, it appears fast and responsive and seems to perform normally. It would be interesting to see what impact switching from gtk-greeter to unity-greeter on LightDM would have on this.
On the 64-bit version only, remnants of prior (completely deleted and purged) kernels cause occasional behind the scenes non-fatal crashes. An "update-grub" in the installed system should resolve this (but no guarantees.) "apport" has been disabled in both 64 and 32-bit versions (as was common practice in prior LTS release.) Further swappiness has been set to 20 (a much more sensible default than 60.)
After rebooting into your newly installed system, navigate to the Synaptic Package manager and check your repositories and options (Menu -- Administration -- Synaptic Package Manager.) The "Backports" repository may be enabled (although it was disabled before the squashfs and .iso were repacked.) It is not known at this time why it gets re-enabled in conjunction with the install. It was briefly enable to retrieve and install "scratch" dependencies but was quickly then disabled after they were downloaded and installed.