When Google starts to roll out an update, then there is no stopping them. A month back they launched Jelly Bean 4.2 and today they have launched the update for Jelly Bean 4.2.1. This update is for all those lucky Nexus users only. The new 4.2.1 OTA update fixes two things.
1) Fixed the December Bug . Those who do not know how this, the month December never showed in the Contacts App.
2) Fixed Bluetooth Issues.
The 1.1 MB update is currently only for LG Nexus 4, Asus Nexus &, and Samsung Nexus 10 and it will be available for Galaxy Nexus users next month. If you have not received this update yet in your country, just be patient as it is on its way.