Apparently some game developers (those lucky few) have been given an iPhone 4 equipped with the A5 chip. This is the same chip that has done wonders for the iPad2, making it quite a bit faster than the original iPad. These iPhone 4 looking devices are likely to be iPhone 5 prototypes.
The latest rumors put the iPhone 5 in an Apple store near you sometime around September. I also heard a rumor that the prototype is being referred to as the iPhone 4S, though with the massive power enhancement I think it will get it's own number... 5!