I've had my QC2's for more than 2 years, and noticed last week that the infamous cracks were starting to appear (guess I've been luckier in that respect than many; I've heard of the cracks appearing in as little as 6 months). I decided to take a chance this evening and brought them to the Bose kiosk at the Mayfair Mall in Milwaukee. I told the gentleman manning the kiosk that I was having a problem with my headphones and was looking for some guidance.
He immediately admitted that this was a chronic problem with that model and that they were swapping them out with the new improved QC2 design. He handed me a brand new box, logged a quick transaction into his point of sale system, and sent me on my way. At no time was I asked for a receipt or even when or where I'd bought them.
Interestingly, the updated QC2s seem more comfortable; the ear cushions are "cushier" and easier to get around my Dumbo-sized ears. They also seem to do a better job of sealing against my head.
I'm quite pleased!