Aside from the introduction of the Nexus 7, the big reveal out of Google I/O was the announcement of Jelly Bean. The update promised to bring speed to the Android OS with Project Butter, resulting in smooth 60fps animations and transitions, as well as some smaller tweaks. Now Google has officially released the Jelly Bean source code, merging it into the current AOSP codebase.
Jean-Baptiste Queru took to Google Groups last night to make the announcement, detailing how proprietary binaries will also be available for the Nexus 7 and Galaxy Nexus. Don’t worry too much about older devices, as Nexus S and Xoom binaries will be coming in the future. Now that Jelly Bean is being merged into the AOSP, custom ROM makers will be able to take advantage of the latest code and put out some new ROMs for a wide variety of devices.
The CyanogenMod team has already expressed their interest in getting a far-reaching Jelly Bean ROM up to speed as soon as work on CM9 (which is based off Ice Cream Sandwich) has been finalized and released. In the meantime, you can expect smaller groups and individuals to pump out some ROMs for popular devices. Keep a close eye on xda-developers.