I've read that Youtube had a warning all day, and that this is just scheduled maintenance. Don't know if it's true or not, though. Could be teh haxx0rs.
It had the normal maintenance warning up just a couple of minutes before I refreshed and that the "All Your Videos Are Belong To Us" screen, so who knows. Maybe they just did it themselves for a joke. I sure hope so because I had some videos on there.
Now it says: Whatever. Getting hacked was a legit possibility. Could still be in fact. Those hackers might be doubly amused.