Question: Will Modern Warfare3 (Xbox live) add more gametypes to matchmaking list?
Like One in the Chamber to add or Gun Game
Infected game type was added after release..
Answer:
Yes. they said they were bringing more out in April. If this wasn't to happen then they were to come out in September.
They definitely won't be adding one in the chamber or gun game unfortunately, but maybe something else though I doubt they will add many more game types/playlists.