It could be a transistor, maybe used to control voltage going to the VGA port. As for damage, well all it probably means is that a function of your motherboard won't be possible, like VGA port - it's unlikely that you'll cause more damage, and it's the sort of thing that could be fixed if it became a real problem.
I'd wing it, just keep an eye on it for a while, make sure it's not overheating. Motherboards can be incredibly resiliant to damage, I've seen motherboards work fine with leaking capacitors and all sorts, even rust!.

Health, Ammo, and bacon and eggs!
