Call of Duty 2 I think had that on the Xbox 360. Up to 4 people on the same 360 going online. 2 people could even share a gamertag if one didnt have one himself. They just got called "[player 1's gamertag](1)" or something.
I wonder if we will be able to have bots/AI replace humans. For example if a room is taking a while to fill and there are only 2 or 3 of us could we put a few AIs in the grid.