Well I finally got to play it tonight and think it's great. It's not mind blowing, but I'm getting what I expect out of a sequel. I'm especially impressed with the MP maps so far. They seem bigger and with lots of options on where to go. I'm definitely impressed with the amount of shit they packed into MP mode now, with all the accolades, perks, challenges, kill streak options, etc. I'm still wondering why they give you the option to choose your rank insignia...I suppose if you're level 55 and want to wear PFC stripes you can do that, but not sure why. Multiplayer has ran just fine, doesn't seem any different than MW1 in terms of lag.
This is for the 360, btw. For anyone skipping the PC version but still plan on getting it for console (blasphemy!), it's solid. Won't be disappointed.