Single player is breathtaking and enjoyable, multiplayer is your call.
The story was great, the combat was great. There were many guns and worth the money. I loved the twists and turns and the challenges. I wish the story was more than just a couple of hours which I beat. Was it worth the hype? Yes, I think so but I wish they added more to the story. After the end of MW2 *spoiler*, they shouldn't have just end it RIGHT there. Do we really need a MW3? I think 2 was way enough and what I was trying to hope for. A little bit disappointed but don't let that get you. Stealth mode was fun and I loved seeing Price again. Poor Ghost though.
Multiplayer: your call, I'm not a huge fan of playing online on FPS (too many elites.) From what I seen, it looks enjoyable but that is if you know how to kill people without random gunning like you'll probably do in single player campaigns. This game requires a mic and strategy thinking. There would be no way to win by just gunning down people (unless you're into team deathmatch but what fun is that?!)
8.5/10.