I'm selling one on eBay. I set the starting price at 99¢ to attract bidders, and it worked. Within 24 hours it had a dozen bids a few watchers and was up to $76! I've had about 100 auctions on eBay and I've never seen anything like this happen before. If you are in the market for an iSight, you can expect to pay a premium, just like the original Airport card after Apple discontinued it.
Both these products are interesting in the same way. There was nothing special about the Airport card, it was a standard PCM-CIA style card just like every other card on the market. But it (AFAIK) is the only one that was short enough to fit inside Apple laptops and had an antenna port to boot! The iSight, while not revolutionary is just better designed, especially in the mounting hardware, i.e. laptop clip and magnetic mount for their aluminum displays. Apple does not generally innovate completely new products, but they do an excellent job of taking existing technologies and making them work far better than the competition.