At this stage of the proceedings, Foxconn must be churning a billion iPhone 5 units per second, getting ready for September 12. Unsurprisingly, it seems someone managed to smuggle one of them out of a factory in Jincheng, China. Not just parts, but an entire unit.
The phone seems complete and booting. It stops just before showing the unlock screen with this error:
This device is not registered as part of the iPhone Developer Program. If you are a member of the program, please register your device in the @@[email protected]@.
After all the leaks, it seems highly unlikely that this is any kind of prank or fake — unless Apple has played the biggest deception operation since World War II.