I'm kinda' bummed at how everything seems to be slowing moving towards competitive MP. I miss the days where an FPS had an awesome story behind it, had a really well done SP campaign.
What I'd like to see is a proper sci-fi FPS. I've mentioned this before- not one that takes place entirely on a planet, how about one that takes place in space, where your ship is being seiged? Fighting in the corridors, dodging and ducking from room to room for cover, periodically stumbling into a bogie and engaging in a little hand-to-hand combat.
I could see a branch off of CoD doing this. And for MP, why not have a Co-Op mode? Where you and some buddies can tackle the "SP" campaign together? I think that'd be a freakin' hoot, and likely why I enjoy the L4D games so much.
Anyhow, as to this CoD, I think I'll still enjoy the SP quite a bit. I've yet to buy WaW and MW2, maybe I'll get 'em on sale later this year and play 'em before I play this one.