The guys over at Game Chronicles recently had an interview with Infinity Ward's Vince Zampella. The main question everyone is wanting to know....will there be single player coop? Well......
GCM: What’s new this year for multiplayer? Will you be re-mastering any old levels using the new engine, and will there be cooperative campaign play?
Vince Zampella: It’s a mix of favorites from the original brought into the new engine plus levels from the new single-player game and some original multiplayer levels, about a dozen multiplayer maps in all. There will be no co-op gameplay, but it will happen eventually.
Looks like the answers a no for now but who knows what the future holds.