Android 4.2 had a pretty annoying bug. While it didn't break the device in a catastrophic way, it did prevent users from entering the month of December into anything that used that native date picker in several apps. This meant that birthdays, anniversaries, and the like could not be entered into a contact's information.
Google has begun rolling out updates to the Nexus 4, Nexus 7, and Nexus 10 to fix this bug. The update will bring the device's Android version to 4.2.1 and should hopefully make this strange bug extinct. While most of the media was focused on this December bug, all of Android 4.2 seemed a big buggy, with problems extending to Bluetooth and other areas.
The update comes in at a tiny 1.1MB, so it's unlikely to come with any exciting new features. The update appears to address only the problems and bugs that were present in 4.2. It's nice to see a company work quickly to resolve issues that are present in the software it produces as sometimes companies can be slow to respond to issues reported.