Oh my goodness, ladies and gentlemen! It's the iPhone 5! Not really. I'm just pulling your leg. What you're actually looking at is a Chinese knockoff of the next iDevice, based partly on the leaked designs that we've been seing lately.
The one you see here pays tribute to the iPhone 3G(S) bodystyle by returning to a curved back. That curve isn't very popular when setting your phone on a table and trying to play Angry Birds, but it does feel better in the hand. It also looks pretty nice, to boot.
This particular knockoff is also thinner than the current, official iteration of the iPhone. At 9.3mm thick, the iPhone 4 is about 2.3mm thicker than this one, which is a mere 7mm.
The iPhone 5/4G/4S/4GS/Mega Awesome Edition is set to roll out in September/October, right alongside iOS 5.[Mac Rumors]