Google launches the update Jelly Bean 4.1.2 and is available for the Google Nexus 7 tablet and the Android Open Source Project mirrors. The update comes with the an OTA for the Nexus 7, which now benefits from a landscape-capable default launcher. Another feature present is a one-touch notification center.The update is merged into CyanogenMod 10 and is too fast for the merge which is just announced.
(Thanks to http://www.xda-developers.com)
The build number is JZO54K and the AOSP tags are android-4.1.2_r1 and jb-mr0-release.
Google says the update improves performance and stability and fixes bugs. But its reported that it is not much useful, but definitely it is a start and many more updates are to roll out. Google request to make the update soon it arrives and the future variants of the grouper hardware will have a minor change in one of the components that will not be compatible with 4.1.1.
We give here the manual method of rooting the update.
Official Google link : http://v21.lscache1.c.android.clients.google.com/packages/data/ota/google_nakasi/03a4eaf95f73.signed-nakasi-JZO54K-from-JRO03D.03a4eaf9.zip
1. Root your Nexus 7
2. flash ClockworkMod Recovery
3. Download Android 4.1.2 Jelly Bean JZO54K
4. Place it directly under /sdcard
5. Reboot to ClockworkMod (CWM) Recovery.
6. Navigate to install zip from sdcard