GoW is by far the best game ever made, now with that said I only have a few suggestions that would in my mind improve GoW 2 & destroy the competition.
1. Please please use matchmaking so I don't have to jump in a 19 round match & watch some noob or little kid quit after the first round.
2. Also develop a better rank system so everyone can play with someone on the same skill level like Halo 3 . I'm pretty sure that every one that plays this game and is good at it would agree with me.
3. Keep all the maps from GoW 1 which should be a no brainer.
4. Now this is probably the best idea ever!!! To me at least. If you don't use matchmaking or a rank system set a rule that if you quit a ranked match your unable to play ranked matches for at least a week or something like that, and kick to person to player matches only for that week. Obviously this would not even be an issue if you used Matchmaking like Halo 3 which would take this franchise completely to another level.