The interesting part of the Rage demo is that Carmack took the time to get it working even on the 2007 iPhone without looking that different then what was on the iPhone 4. And both were pulling in megatexture assets.

Comparing the two side by side, the Rage demo was far more impressive then the Unreal Engine 3 one.

Unreal Engine 3


Rage (unfortunately not a lot of good stills out there)


The rage tech should be shipping in an iPhone game by the end of the year, with a second iPhone game planned alongside the 2011 PC/Console game release.