Bored of waiting for your OTA update? Google has now made Android 4.1.2 factory images available for download for the Galaxy Nexus and Nexus 7.
The images as supplied with a flashing script, but be aware that flashing will wipe your device unless you manually flash the various images leaving out the userdata partition.
What are you waiting for? Head on over to the download page. :) MoDaCo Custom ROMs based on the new release will be online shortly.