The servers are melting.
My suggestion is to come back later in the week. All 16 million people who bought this game are trying to log in at the same time. There isn't a server farm in the WORLD that can handle that kind of load without turning into a puddle of goop.
XBL Gamertag: JWRebholz
PSN ID: jwrebholz
...No, I'm not very creative when it comes to this sort of thing.