Short (4-5 hours), redicilus single-player, multiplayer VERY similar to MW2 - overall - same old s***
The problem I have with multiplayer is not that it is bad. Its VERY good and addicting as always, however it looks, feels and plays just like MW2. It could easily be a DLC for MW2 - it truly could. The only new things are few weapons, maps (not that great in my opinion), kill confirmed mode (which is the best part in MW3), and new kill streaks. Are they as new as Activision wants you to believe? Of course not! Assault killstreaks are 90% the same as MW2, Specialist are just perks which you gain in every kill (without it you only have 3 perks of your choice), the only new thing is support killstreaks but they are like a name suggest - support, they are not made for killing people, so if you all about getting frags - your not gonna be a big fan of this package. Its good for xp tho, because this killstreak is not resetting after you're gonna get killed.
Overall - this game is not bad its just as good as all COD games since MW2 - the problem is that the reason for it is a fact that this game feel like a copy-paste kinda thing made for $$$. If you are a fan of the series you're gonna have fun. If not, and you want some great, fresh FPS experience - pass on this one and play some Battlefield 3!