We have had about 3 weeks to play around with AOKP's Build 1 of Android 4.2. They have been hard at work squashin bugs and adding innovative features to their Rom. Some devices that have been added in the latest build are Nexus 7, Nexus 10, and the US variants of the Galaxy S3. The Galaxy Nexus GSM and Verizon versions are supported already along with Nexus 4. I imagine this will be quickly ported to other popular devices as well.
There have been lots of new additions added in this build including Bootanimation picker enhancements, colorable clock views/widgets, Lockscreen options (option to hide initial page hints, start lockscreen with minimized challenge, longpress on minimized challenge to unlock, carousel animation), Navigation bar options (Colorable nav bar background, Recent menu opens faster than ever), Status bar options (Alternative signal layout, New toggle: Sound State ring/vib/silent, Mobile technology indicator reflects internet connection status), Camera (power key shutter), Phone (call statistics), plus more!