It's no surprise that Halo is a monster franchise, a franchise I might add that is very co-op friendly. Despite four Halo games, (1,2, 3 and Halo Wars) - people have an insatiable appetite to kick Covenant ass with their friends by their side.
According to Gamasutra, Halo 3: ODST is the most anticipated Xbox 360 game followed closely by Modern Warfare 2, which we believe might have a co-op mode as well. ODST is actually the game with the highest "intent to purchase" - but MW2 has the highest pre-order intent. What does that mean?
...(it reflects) a somewhat more dedicated audience; that figure represents the proportion of planned purchasers who say they will put advance money down.
If Infinitiy Ward adds a true four player co-op mode, I'll be putting my money down as well.