PlayStation 3 will receive a “minor” firmware update soon. PlayStation 3 system software update, v3.66, improves system stability “during use of PS3 format software and network services.”
These updates normally release a few hours after the notification is sent out, so expect to see it live soon.
PS3 System Software Update (v3.66) [PlayStation Blog]
Update 11:45pm: It’s out now. Go grab it.