Android Central member seanmacanally got an OTA notification on his rooted Verizon Galaxy Nexus, and with a little help from the great crew in the forums got the package pulled and uploaded for everyone to play with. A few caveats:

This is only for the Verizon version of the Galaxy Nexus

It's Android 4.0.4 IMM30B

You will need to be completely stock with stock recovery to install it as-is

This doesn't seem to be an OTA that's going out in full force, so it very well could be some sort of internal testing version. Keep that in mind if you flash it -- things may not be working as well as you would hope.

Manually flashing the OTA package is pretty easy, see the instructions here. And you're going to need the file, which you can download right here. Good luck, and have fun!

Source: Android Central forums