Well MW2 is more cartoonish than this(multiplayer i mean), CPU problems have been fixed, and game recording works on pc.

They did some great balancing - but fucked up one thing at least on pc.
Tube has way less splash, so its not so lethal.
Akimbo weapons are weaker, so no g18 fagging.
Knife lunge range is much lower.

Bad things:
no quickscope on pc - i can understand that auto-ai... i mean 'aim assist' on consoles made quickscope too easy - but it was not so easy on pc, plus it gave opportunity for snipers to defend themselves at close range.
Sniper rifles are nerfed too much, but at least they are usable.
Shotguns are useless, they got nerfed too much.

Game recording is great thing - your recent games are recorded by server and you can download it and watch the game from any perspective. Basically you can record movies without impact on performance from using fraps or something. Plus it will be great tool for spotting wallhackers and aimboters.