There was a thread earlier proposing a sort of badlands combat area. I would want like a moon devoted to this and it would be seperate from the single and co-op game. You would go to this planet to fight in simulated battles with other players to prove your combat skills. None of your solo/co-op achievements would come into play and you would have only your multiplayer stats. Everyone would compete in a halo-esque arena. No loadouts just base weapon spawns. It would have a ranking system based on personal stats. Just my opinion.