Update 2: The blog post is back, and the update should be rolling out today!
Update: It sounds like the blog post announcing the update was published erroneously, and has since been pulled down. While that's definitely a bit of a disappointment, it does mean that the update should be headed out very soon. Just not today. Bummer.
AT&T just announced that its version of the HTC One X will be receiving an update to Android 4.1 starting today.