From what I've read it improves the stability (as if it wasn't already) but is there really anything useful or any new features on this FW update?
Updated my PS3 (60GB edt.) hours after this update was available and everything went smoothly but I've read that again there were people who had their PS3s bricked somehow.

That is a possibility with any update, especially when the origin of the update is downloaded straight to the console. So far I've yet to experience a brick with my own consoles.
