Many PlayStation 3 owners faced system performance issues like freezing, game crashes and other issues after updating to PS3 Firmware 3.00 update. Following that, Sony has now released PS3 firmware 3.01 update for 'improving system stability'.
Eric Lempel, Director PlayStation Network Operations, announced the release of firmware 3.01 at the official Sony PlayStation blog. Lempel calls this an optional update for improving system stability during use of some 'PlayStation 3 format software'.
Appears more like an update with slew of fixes, no new features were mentioned at the time of release.
Again in the comments, Lempel makes it clear - This will fix the issues that some users have experienced with Uncharted: Drake's Fortune. If you notice any changes in the system after applying firmware 3.01 update or continue to have issues, please report them in the comments section below.