
Gearbox has put plenty of work into getting the competitive multiplayer options running smoothly for Internet matches, but unfortunately the cooperative mode that Halo was known for will likely be missing in action. Bungie's producer for the game told us that it might still happen, but it's looking less and less likely, as the team hasn't been able to meet the level of performance that we'd expect. The difference between the competitive and co-op modes is that co-op requires exact synchronization between the players' systems to keep the AI and scripting in lockstep--and that's prevented by the higher latency that Internet connections exhibit.
Meaning its impossible . . . for now . . .
Found here > http://www.gamespot.com/pc/action/halo/ ... 28228.html