My guess would be, at this very moment, at least one Apple employee is becoming an ex-Apple employee, after this seeingly genuine prototype of the brand new iPhone was lost in a bar in Redwood City… And then handed in, not to Apple, but tech site Gizmondo… (The rest of Apple employees I suspect are cowering in corners as Steve Jobs hurls furniture around the office in a blind rage.) ;)
After some close examination, including taking it apart, the phone (which was camouflaged in a case to look like an normal iPhone 3GS) appears to be the real deal.
New features include a front-facing video chat camera, Improved regular back-camera with flash (unfortunately, not the flash we all want on the iPhone, but still nice), a switch to Micro-SIM, improved display, and a bunch of changes to the layout and buttons.
Lots more photos and video over at Gizmondo.