My mac is perfect except for the U key being slightly raised on the left hand side. Am i a bit bummed? Not really, i couldnt really care less. The key works perfectly and as long as it doesn't decide to fall off i don't have a problem with it. Compared to dead pixels, flickering screens, duff dvd drives etc i'll take a crooked key anyday.
If any of you have a slight cosmetic defect on your mac...KEEP IT, its far better than a real hardware fault.
Sure Apple should have 100% perfect quality control, but we are living in the real world remember, so expect some imperfections.