The game has the feel of playing in a summer blockbuster, while the multiplayer portion has become THE standard for FPS.
The solo campaign feels like a summer globetrotting blockbuster. I didn't get caught up in the controversial aspects of the game (by separating what's virtual from what's real), but the story just didn't do it for me the way Modern Warfare 1 did. The plot tries its hand at crafty turns but it leaves a lot of questions unanswered. Disregard the story, and the technical graphics and environments just plain rock, I could do the blazing snowmobile level many times over. Too bad the campaign is so short at around 8-9 hours. Most gamers don't care about that however, since they can spend 100 hours playing multiplayer. Now that I have come to grips with my preferences, I can do much better just renting the game for $3 instead of buying it for $60.
I was kind of let down by the co-op mode, to me it was just more of the same places you played in the campaign. I was hoping for more than just one new map, or others imported from MW1. The missions could have been set up to be much more of a blast for two people to play, such as fighting against a large enemy structure that could benefit from a tactical plan, etc. It feels like an afterthought once the campaign and multiplayer structure was developed.
If you haven't played it by now, it's still going on strong on Xbox Live and worth buying if you can find it cheap. I'm awaiting the rarely seen before atmosphere of Call of Duty Black Ops, fingers crossed the solo campaign will last more than 10 hours.