Just got the notification of an update last night with my Google Nexus 7 and found out it was for the latest Android 4.2 Jellybean.
The update was about 80MB in size and was done in less than 15 minutes.
Announced a couple of weeks ago, Android 4.2 (still codenamed Jellybean) introduced a lot of improvements and fixed a number of bugs from 4.1.2. A complete list of what’s new with Android 4.2 are listed here.
There was a few cosmetic changes in the UI of the Nexus 7, which includes a panel shortcut for the dropdown menu. The panel also includes a profile tile that represents the logged in user (which now supports multiple profiles).
Google also rolled out the same Android 4.2 update to the Galaxy Nexus yesterday.