Apple will replace of course. But if it´s scratched a week later, or even a day after purchase, forget it. And it's prone to scratching.
Now, having said that, there are warnings on various sites (but look at zagg.com) and see the evidence of how easily it gets scratched, on the back cover and on the sides.
We had glass before, and stainless steel. Now we have brushed aluminum and that is going to be a bummer! So protect it folks. Get a Abraham´s Tank (Seidio for example) type of cover for it, or else you´ll be crying soon after purchase.