Developers in the Google Groups discussion were impressed with the inclusion of Jellybean code for Verizon CDMA/LTE versions of the Galaxy Nexus, which had been a sticking point for open-source development in previous iterations. However, AOSP technical lead Jean-Baptiste Queru did note that "there's no AOSP support for new devices other than Nexus 7. Anything beyond that is up to individual OEMs."
According to the Google Groups announcement, proprietary device drivers are already available for download for the Galaxy Nexus smartphone and Nexus 7 tablet. These binaries are designed to be integrated with the existing open-source code to provide full functionality for the devices.
Queru also said that similar binaries would be forthcoming for the Nexus S and Motorola Xoom tablet, timed "to approximately match the timing of the consumer release."
What this means is that Google isn't going to roll out fully functional Jellybean binaries for devices that haven't gotten an official OTA update from their carriers. Users of such devices will have to gain root access and install a custom, third-party ROM - with its own drivers - to use Jellybean right away.
Fortunately, work on those custom ROMs is already well underway. Unofficial Jellybean builds ripped from devices distributed at the recent Google I/O event are already available for some devices, though they sport varying degrees of functionality. Versions created directly from the source code are likely to be far more functional.
The open-source code released also works around the recent court decision that upheld Apple's patent of universal search functionality, so updates and development aren't likely to be delayed by potential legal issues.