Some black MacBook users report that the matte black finish begun peeling and flaking off shortly after they bought their notebook:
Users looking to get their hands on the new matte black MacBook might be in for an unwelcome surprise. It seems that the matte finish on the notebooks is extremely fragile and can be easily damaged. The problem surfaced less than 24 hours after Apple unveiled the new MacBook.
Some users report that the matte black coating on their new MacBook is rather fragile and has begun peeling and flaking off leaving the undercoat exposed. We are not sure yet if the problem is widespread or only occurring on a limited number of black MacBooks but we are looking in to it.