I just noticed a crack on my 5-month-old MacBook. I have never dropped it. Obviously, this is a product defect since I am not the only one. As soon as I get a high-quality picture (this one was taken by my SE w810), I will post it to the “My MacBook Was Cracked By Itself” group on Flickr.

Update: Last week I got the top case replaced at an Apple store. Everything works perfectly now (knock on wood). The new keyboard actually feels smoother than the old one. Also, according to a genius, defects like this should be covered even if the product is out of warranty.