The only way that I'll even consider this one is if Treyarch:
-Gives us actual drivable vehicles like tanks & jeeps; aviation can be called to support you a la every other COD after COD4 & BF2: Modern Combat. And be sure to have them in the campaign as well & not just in gimmicky sections, but can actually be used by a player at will.
-Gives us a good variety of maps that can accomodate all styles of play (CQB, sniper wars, vehicular combat, killstreak wars, etc.)
-Gives us a campaign that focuses a bit more on black ops & actually allows for some decent approaches to gameplay at the player's discretion. Maybe even some co-op campaign work, since you can focus on killing off two characters in one!
-Take MW3's survival mode & work it in alongside zombies. Have Spetznaz assassins, snipers, Juggernauts, KGB trap experts, GRU operatives Mi-24 Hind helicopters & even some armored vehicles. Allow it to accomodate up to 4 players in either split-screen, LAN, or online matches.