And Cherrypye, THANK YOU! I just got my laptop back from the Beverly Center Apple store and you were so right. They replaced the entire case for me, new keyboard and everything, free of charge.
The tech explained that often he sees this happening and he thinks its because people shut the laptop too forcefully over time. He explained that there are tiny magnets in the outer corners of the laptop, and that if you get the end close enough, it actually will close itself, so there's no reason to slam it shut. He was so nice, really explained everything to me.
I also had issues with the bottom getting overheated and the plastic has actually become scorched and turned slightly brown. THe tech explained to me that the problem is using my laptop on my lap, and not allowing the heat to be fanned off because the vent is covered. So he showed me this cool laptop pad that vents the computer and has a fan on the bottom. Its AMAZING. Here: The Apple Store (U.S.) - Belkin Laptop Pad
And I had previously taken it into the Apple store at South Coast Plaza and I knew more than the tech. So the Beverly Center referral was amazing- thank you!!!