That came out of left field. RIM has released a quick update for the BlackBerry PlayBook OS bringing it to v18.104.22.1688. The update is about 79 Megabytes so its not a complete overhaul and probably makes use of QNX’s differential updates. There is no word on what is in the update since the description is the same as the 2.1 release.
So what are you waiting for? Hit that Check for Updates button now!