CoD4 with better Grapchics should do it
Online co-op Campaign, for those of us who have no real friends.
After beating Campaign, to be able to play it with your online character (So, with perks and stuff, so you can have some real fun)
New type of online gameplay (Be able to select 'Knifes only' for example).
No stupid perks like Commando (Knifing at 7m, seriously?), or useless perks like Scrambler.
Preferably test the game before launching it, so there are less 'Model 1887' type shenanigans.
Make Surpressed Sniper Rifles actually worth something.
Different kinds of customizable 'avatars' (So, being able to select different models of Ghillie for your sniper, for example).
A kind of equipment, some kind of health pack, which gives you a quick full-health when in dire need.
No Tactical Insertion, or somehow limit it.
I apologize for small wall of text.