That hotly anticipated Android 4.2.2 update for the AT&T HTC One was approved for distribution yesterday, but now it's reportedly hitting devices. Users on XDA report that a small 16MB update is showing up first, then sometime later, the big 537MB update to Android 4.2.2 appears.
This update will add most of the Sense 5 features from the current flagship HTC One, but any features that rely on hardware like the Ultrapixel camera aren't included. HTC has updated the info page to include the One X (it already listed the X+) – it looks like there won't be any difference in the feature set.
Some users are reporting that after the smaller OTA shows up, setting the clock ahead a day can prompt the 537MB update file to present itself. We'll update if we get any more info on that.