long story short, they carry a 3 year warranty in the USA for EVGA. Their return process is spectacular so you have nothing to worry about till then =)
The new generations of cards are pretty hard to kill. Temp is the biggest problem and all the new cards thermal throttle rather than cook. As posted above, the fans are most likely the thing to go and can be replaced. This is the reason you start to see longer and longer warranties. If you get a good card that is working properly, you should get years out of it. I would think that you won't be able to efficiently mine with it before it dies.