A recent survey (if you call polling 1,500 people a true survey) says that 1 out of 5 Apple MacBooks are significantly discolored. Maybe not a big deal to most as most Apple users are extremely happy with the Mac. However, why mess up that nice, smooth, plastic surface if it can be prevented? I am sure Apple is aware of the size of the problem and is just keeping quiet until they have to do something. Anyway, here is some advice- don’t buy first generation products! Wait until they get all the bugs worked out ;).
Engadget has some pictures of the problem.