I'd say it depends on what comes of MW3. To be honest, I didn't like the campaign of Blops all that much, it never really felt like it involved the player. Hmm...how to quantify that...well, you can get through the whole first proper mission without firing a single shot. Never tried myself, but watched a youtube video of it. The interrogation scenes were simply irritating to the point of teeth gnashing.
It's a shame really, because I really, really enjoyed COD4, and I know they were on to a good thing there, it's just a pity they couldn't seem to replicate it effectively. But by god that game was awesome when I first experienced it. It was like breaking me into this world of FPS war games all over again. But now, I feel like I'm simply done with them.
Always go back to Rainbow 6: Vegas 2 though, can't get enough of that semi-real tactical shooting stuff, hope something else like that comes out soon.