Although firmware update 3.00 really is a huge update, the majority of PlayStation 3 owners haven't responded too favorably.
And perhaps the biggest issue has started to reveal itself: you will find similar complaints in most all game forums online, but you can check out this steadily growing thread in the official PlayStation forums to get the gist. Basically, it seems as if the recent update is causing problems with the Dual Shock 3 (but not with the Sixaxis, apparently). A few users are being even more specific in saying that it's the Ceramic White DS3 that's the victim more often than not, although the problem seems to extend to any DS3 out there. What happens is that while the LED lights function, telling you the controller is activated, you can't actually do anything. One simple solution is to simply re-sync the controller with the system after the update has completed, but that doesn't apparently work for everyone. For my part, I had this happen to my silver Dual Shock 3, but after restarting the machine (I have the new Slim), everything was fine.
Anyway, we'll see what Sony has to say about this; the good news is that this bug doesn't appear to be infecting massive groups of PS3 owners. Hopefully, it's nothing too serious.