Google open-source guru Jean-Baptiste Queru has announced on the Android Building group that the Android 4.2.2 source code will shortly begin pushing to AOSP -- the Android Open-Source Project. The build number is the same as what's now being pushed to Nexus devices -- JDQ39 -- and the tag is android-4.2.2_r1.
In addition, proprietary bits for all supported devices have been published online, and Android 4.2.2 factory images are also available from Google's developer site. Significantly, JBQ points out the Nexus 4 and Nexus 7 (all variants) now have a full set of proprietary binaries available online, bringing full AOSP support to these devices.
Good news for those wanting to roll their own Android, as well as anyone looking forward to Android 4.2.2 ROMs for other devices. Download info for the Nexus binaries can be found at the link below.
More: Google Developers