AppleTV OS 2.3.1
Released Febraury 25, 2009
No information yet. Expect plugins to break. Users on Twitter and other sources report patchstick is working to re-enable ssh access after the update.
Several sources report patchstick still working. Boxee will be disabled after applying the update, but can be enabled by reapplying the patchstick 
- Official Apple TV software updates info
- Announcement on Apple TV Hacks
- Article on TUAW/The Unofficial Apple Weblog