Guys here’s the Jelly Bean Wallpapers and Boot Animation which were ripped off some hours ago and now is ready for download. All the official files have been nabbed from an OTA update for the GSM Galaxy Nexus that was handed out to I/O attendees.
You can download now boot animation and wallpapers from Android Authority and Droid Life respectively. your device needed to be rooted to use these packs. Get them from source links below and get ready for Jelly Beans. Simply copy the .zip to your device and then with the file manager of your choice, move it to system/media/bootanimation.zip.