~More character customization, like custom Camo, Voice, Etc.
~More weapon customization, more camos and maybe different knives and stuff
~Make it a bit harder to kill people or balance the weapons so that either stopping power or juggernaut aren't a must have in regular.
~A Ten Kill Streak bonus of some sort.
~Stat tracking on par with that of Call of Duty: World at War
~Capture the Flag =D
~A new game mode of some sort. Maybe something like Oddball from Halo would be pretty cool
~A Nazi Zombies-esque mode
~More playlists in Matchmaking. An MLG Variant playlist would be wicked sweet, since thats all I play on Gamebattles anymore.