Indeed, that is odd for an LCD panel. It almost seems like something internal has collapsed, or like you noted - something fell inward. Without knowing either way, it's hard to determine how easy - or inexpensively - it can be fixed. I can't even offer a diagnosis.
Have you been able to send this link or picture in to our service center? It's out of warranty, but it can't hurt to ask.
I've had this tv a few years now, just recently something weird has happened. I noticed a black strip at the top left corner of the TV. At first I thought this could be a burned out pixel issue, however the angle of it is very strange, it looks like more something has fallen behind or infront of the LCDs blocking the light from coming through. I'm posting a link to a picture of the problem. I've tried to talk to Samsung about it, but they don't seem to get the problem. If I'm correct, and something has fallen behind the LCDs, is it easilly fixed?