I am continuing work on my custom, from-scratch, game engine for iPhone, iPod, and iPad. It is a great challenge to implement the various shader paths and allow the engine to scale up and down to accomodate variations in CPU, GPU, memory limitations, and scene complexity.
The iPad 2's A5 chip could be used for a real competitor to the XBOX 360 and PS3. It has proven to be capable of rendering PSSM (Parallel Split Shadow Mapping) and DOF (Depth of Field) in real-time. It makes me wonder if an A5 based Apple TV will have official support for Bluetooth gaming peripherals.