If you have a European or Asian model One X (read: Not AT&T), start frantically hitting that check update button - it's
peanut butter jelly Jelly Bean time. We're hearing from multiple sources that HTC is beginning to roll out Jelly Bean to the One X in various regions today.
This update brings Android 4.1.1 and Sense 4+. Expandable notifications, Google Now, and some fairly minor tweaks like a new Gallery app in Sense are in tow. Sense also now has wonky holo blue highlights throughout the OS, so that's cool, I guess.
If you can't see the update on your phone, we've got a pretty easy explanation: your particular CID (a regional hardware identifier code, typically by country or carrier) hasn't had Jelly Bean rolled out to it. My European One X, for example, is CID 001, but has not received the update. In fact, we have no confirmations of any European CIDs receiving the OTA yet.
Here are the CIDs we have confirmation on so far:
621: Taiwan (already rolled out last month)
As the day goes on, expect a lot more CIDs to be added. And if your One X has received the Jelly Bean update, be sure to let us know your CID! This can be done with a simple CID retrieval app (like this one). Alternatively, if you're a DIY'er, just load your One X into fastboot mode and open up a command prompt and type "fastboot getvar cid" - that'll do the trick, too. Here are some screenshots of the Jelly Bean build on an 044 CID One X.
Note that there will be two updates to get the OTA - a small "battery fix" update, followed by the larger Jelly Bean update.