-Custom Camos: Lots of different camos, you just choose the colors to put into the design
-Infinity Ward already said there is no One Man Army, Commando, and Game ending nuke so good
-No Stopping Power: This leaves room to pick perks such as cold-blooded or hardline
-Killstreaks would be based by score such as 100 points equals 1 kill towards your killstreak except in free-for-all where 50 points goes towards your killstreak so to encourage people to actually take objectives in objective game modes
-More killstreaks, like 3 killstreaks for killstreaks requiring 3 kills, 3 kills requiring 4 kills, etc. all the way to 15 or maybe 20, if you dont like killstreaks go to pure game modes so they get taken out, also killstreaks will be nonstackable
-Killstreak cycle: Cycle through your killstreaks to pick which one to use instead of having to use the current killstreak to get to the one behind it
-Hardcore variation of every game mode
-War: my favorite game mode in all of Call of Duty
-More small maps, ranging from Shipment size to Scrapyard size, maybe like 4 in total because i read somewhere that there is going to be 20 multiplayer maps on the disc
-Custom Emblems: Just like black ops but maybe even more layers like 20
-Custom Titles: Like FNG in MW2 but you write your own
-Custom backgrounds: basically what goes behind the title and maybe a lot of premade backgrounds too
-No Deathstreaks, just my personal opinion, some poeple like them cause it helped but i didnt like martydom or final stand
-Same secondary weapon style as MW2
-More weapons, like 10 or more of each type like assault rifles, shotguns, etc.
-Cool assassinations like halo where you do a short cut scene if you knife people in the back
-Some type of armory system where you completely customize your character and make it your own such as choosing their clothes, glasses, gloves, shoes, skin color, nose size, etc.
-3 disc pack, like Campaign on one disc, Spec Ops on the other, and Multiplayer on the third
-Co-op campaign and a very long and linear campaign, minimum of like 20 hours to complete it
-More private match options than even halo (which will be hard to do)
-Combat Training to be offline to keep it seperated from online
-Combat Training bots to be able to play any game mode and have about 10 difficulties
-Combat Training to have all the features of actual multiplayer and their own leaderboards, each one though seperated by difficulty, like you have different accs for each difficulty, such as leveling on difficulty 1 doesnt increase your level on difficulty 10
-Up to 24 players online and combat training
-Night version of maps
-different goggles, like Call of Duty 4: Modern Warfare had night vision googles but have more options like Thermal, Snake vision, etc.
-More perk pro levels such as Hardline --> Hardline Pro --> Hardline Elite or something like that
-I heard CoD points are not returning which means no wager matches
-Contracts but just for XP (I dont know what you would buy them with though)
-Cheats for campaign after you beat it but the cheats can only be used on the difficulty you beat the mission on, just like goldeneye for the N64, but more options such as ac-130 missiles replace your bullets, god mode, ufo mode, etc.
-DLC to include spec ops missions, new maps, and maybe some campaign missions to answer some unanswered questions or things like Ghost's backstory
-maybe DLC for MW2 and/or MW maps (some of them or all of them)
-some new game modes for online like infection or VIP (change it to make it your own though if its copyrighted)
-interactable maps like Radiation where you can close the doors in the middle of the map or Kowloon with the ziplines
-i would like some really cool chase scene parts for levels in campaign and for MacMillan to return in MW3 and for missions like One Shot, One Kill
That's all i can think of for now, but I'll post if i get any new ideas