Android 4.2.2 was just leaked 2 days ago and being *slowly* updated to many Nexus devices right now. Well, one of the first (if not the first) Nexus device to get a fully, rooted version is the Galaxy Nexus.
Currently this is ONLY available for GSM and Verizon Galaxy Nexus users but it shouldn’t be too long before Android 4.2.2 is spread all over custom ROMs by next week.
Some of the major changes include performance improvements and also quick toggling WiFi and Bluetooth by doing long-press.
I don’t recommend any one to unroot to get the lates