I'm not exactly sure about ATi, but I know of companies that offer RMA for a good length of time (3-5 years) but thats from the date it was manufactured not the date you bought it. It's something to think about, but at the same time, it's more than likely the card isn't even 1-2 years old yet, and by the time it hits 3, it'll be a $40 vid card, probably not even worth waiting for an RMA.
But I'll recommend one thing; track your shipping on it, and as soon as you see they received your shipment, call their customer support and ask your RMA be expedited. You'll likely shave your return time in half by doing so.