Due to popular demand, I have created a MW2 thread so you guys who are discussing how awesome the game is on a thread protesting the lack of dedicated servers can do so in ease.
Campaign-wise, the American levels were explosive fun, but the 141 levels often left you with few or no friends, who could not protect you from swarms of screaming communists. Still too short, and the story was underdeveloped, but it was fun from a gameplay perspective.
Spec-Ops mostly felt like time trial versions of all the levels, but the vehicle ones and the reduxs of COD4 were all fun.
On Multiplayer, the lack of dedicated servers is pretty bad, and I noticed several connection errors that were total BS. Gameplay wise, none of the weapons were as overpowered as I have thought they would have been, but some of the killstreaks (AC-130, PaveLow, and Harrier, to be exact) felt really unbalanced.
So all in all, I was pleasantly surprised. Good job IW.