I've had the classic, 'burn out in the first month' happen twice. A friend's computer vid card just died at slightly over a year, due to fan failing and board burnout soon after. A fan (usually pretty cheap) can take out the card.
I like the long warranties, in part, because, years down the road, they may have to replace the old dead card with some newer part, as they may not have the old card in stock themselves. Saw a couple of threads of people with gt8800s getting newer models back due to this. The trick, of course, is registering your card or keeping your receipt.