It's gotta be related to the update they just released. DOD was working fine for me earlier, I dropped out to do some stuff and the game updated when I started it up again. Now I get the same thing. If you open console you can see the error of "Invalid Steam Key Size" or something similar. The servers probably need to have the update applied before we can play again. At least I hope so; Sure would suck to be unable to play for days due to another botched update.