A while ago we were let in on a secret project in the works by iPhone developer Christian Whitehead. He is responsible for the iPhone Retro Engine and Retro Engine Development Kit or RDSK. Using the RDSK, Whitehead is able to develop classic 2D games in a fraction of the time it would take to build them from scratch with performance levels that literally blow the games Sega has released so far out of the water.
He built this Sonic CD proof of concept, without the use of the original game's source code or a disassembly. The video is really impressive and shows Sonic CD running at 60 frames per second on an iPod Touch.
Whitehead has actually been in contact with Sega regarding doing an enhanced port of Sonic CD for the iPhone, but Sega's challenge to their fans to come up with what they want to see them produce next has pushed the developer into making this project public.