Just received an OTA update of Jelly Bean 4.2.1 on my Nexus 10 and Nexus 7.
I assume this is to fix a few of the Jelly Bean 4.2 issues.
Can't do my Nexus 7 as battery is too depleted, but the OTA on my Nexus 10 seems to have installed OK.
Lost root, but VOODOO ROOT KEEPER restored root OK.
Will try Nexus 7 a bit later.
Sent from my Nexus 10 using Tapatalk 2