It wouldn't be a system update without problems now, would it? Firmware 3.0 is out for PlayStation 3 and some users are reporting issues, most notably a glitch that is causing Uncharted: Drake's Fortune to freeze at a certain point in the game.
The freezing bug doesn't seem to be affecting everyone, but a number of people have been complaining on the official PlayStation forums. Things start messing up after the U-boat section when Drake learns to shoot while hanging. Once affected players reach that area, the whole game locks up and they need to restart the PS3 in order to do anything.
A few people are also saying that Wipeout HD will no longer output in dolby digital 5.0 ever since they installed the new Firmware. Apparently this is the only game affected.
Like I said, it wouldn't be a system update without this kind of nonsense, but hopefully Sony looks into these issues soon. You might want to check and make sure your own PS3 isn't affected.