I've had hard disks fail in a PVR setup (heavy load), I've had memory fail, I've had motherboards fail, I've had power supplies fail, and I've literally typed laptop keyboards to death in ~2 years. I'd be utterly unsurprised about a GPU failure.

The best case scenario is "selling it because I'm buying a new one", the worst case scenario is "selling it because it's starting to flake out", and "selling it because the warranty ran out" is not much better.