I was supremely interested in Respawn's next title, and I'm still impressed by what they've achieved, but I can't look past the exclusion of single player. They noted in an interview with Game Informer magazine that they felt that most players barely played the single player, and went straight to multiplayer (thus rendering single player campaign development a waste of resources). Unfortunately, I think they forgot that they were working on Call of Duty their entire time at Infinity Ward. Call of Duty players normally don't care for narrative complexity, and just want to play online. That doesn't mean that everyone is going to feel the same way about a new IP. I'm sure the multiplayer will be excellent, but I'm not going to spend 60 dollars for an online experience only.
Remember Brink? That was singleplayer elements done via multiplayer. It wasn't as good as everyone thought it was going to be.