It seems that a few iPhone users are encountering problems with the iPhone's touch screen, prompting Apple to replace some units.
Posters on Apple's support discussion boards and forums belonging to both AppleInsider and MacRumors have complained of dead spots on their iPhone's touch screen, almost like the old floor at the old Boston Garden. On a phone based almost entirely around touch-screen input, this would obviously be a serious problem.
It's not at all clear how widespread a problem this is. There were several active discussions about the problem on Apple's own support forums, noted by AppleInsider and others, but they appear to have been recently pulled from the site. Other Apple-hosted threads are still active, with fewer individuals complaining of dead spots on their iPhone screens.
Apple appears to be replacing iPhones for customers who have encountered this problem, according to AppleInsider's report and the forum postings. An Apple representative did not immediately return a call seeking more information about the problem.