12th Feb - News of Android 4.2.2 first surfaced (here). Checked for an OTA update but nothing came up. Googled up this website (How to Get the Nexus 7 Android 4.2.2 Update Right Now), but didn't work for me.
13th Feb - Flashable zips of Android 4.2.2 for Nexus 7 appeared (here). Click here to read the changelog. Battery life supposedly improved after the upgrade (here). From 8 hours to 10 hours? I barely squeezed 6 hours of screen time out of mine.
14th Feb - Still no OTA update.
15th Feb - Nexus Factory Images for Android 4.2.2 Now Available (here). But still no OTA update!
16th Feb - Finally!