I actually JUST went from a 2.0 CD MBP to a 2.2 SR C2D MBP. I have to say, maybe I was lucky, but I have had no yellowing issues, the screen is perfect. The lid closes fine. Also it runs A LOT cooler, the screen is brighter and more clear and I definitely get a better battery life because of the LED screen. The screen itself seems to sit higher up in the top bezel (not sure how to explain this, but before I had a larger amount of plastic/edge around the top of the screen (where the isight sits) and now it's more symmetrical with the bottom.
I purchased mine as a refurb, which may be the reason I had a so far (4 weeks and counting) a problem free lappy, as it had already been checked over for any defects twice over.
It's peppier then my last one by a good bit as well, and like I said runs a lot cooler, the fans have only gone one once while I was using VMfusion with solidworks and doing heavy rendering.
I don't game so I can't help you in that respect, but I'm sure it's great.
edit :i read your first post wrong, sorry. Thought you said MBP not MB. I've heard nothing but great things about the macbook actually, best one so far apparently. I think WOW plays fine on it but have no first hand experience. There is more and more good indication that there will be a more portable version of the MBP coming out soon though, so either way if I were you, I'd wait to see what January brings.