BUMP
Because I need an answer to this question, my CD MB started turning grey around the palm rest and trackpad after 2 weeks, Apple are sending me a new C2D (which was lovely of them) and I need to know if the same thing will happen.
As far as i'm concerned this is unacceptable, plastic should not change colour, dirt should wipe off. I'd accept a tainted MB after 2 years or so of use, but not after 2 weeks, or even 5 months.
Answers/experiences people!