The PlayStation 3's latest update, version 4.45, was just released. You may see the usual message telling you to update, but don't do it yet. Thank me later.
It's normal to see reports of system issues after new firmware has been released, but there's a serious cause for concern right now. Hundreds and gamers are reporting bricked consoles after installing the latest update. The symptoms are the same across the board; after applying the update and restarting the console won't boot past the welcome screen.
The scariest part about all of this is it doesn't appear to be isolated. There are fat, slim, stock hard drive, and aftermarket hard drive consoles being affected. Nobody is safe.
I installed the update before the issues began flowing onto the internet like a waterfall and so far my console seems okay (I'm in the middle of watching Game of Thrones right now), but I wouldn't try your luck if I were you. Sony should be pulling this update by day's end, and soon it'll be re-published without the show-stopping bug.
If you happen to be affected by this issue then don't worry, your PS3 won't be rendered an expensive doorstop. There will be a fix released that you can then install using a USB drive that will correct the problem for you. Well, there should be, anyway.