After hitting the AOSP servers, Android build JRO03L of Jelly Bean has already been turned into a custom ROM that is ready for flashing on the VZW Galaxy Nexus and Google’s Nexus 7 tablet. It’s still Android 4.1.1 and there is no official changelog that we’ve seen yet. If you’re in a flashing mood, simply download this file and flash through ClockworkMod. A wipe is recommended if coming from anything else.
Download: JRO03L for Galaxy Nexus 4G LTE | Nexus 7