Apparently Nintendo have been registering patents for a process called "displacement mapping" which allows better quality graphics even in low-tech systems...

Could the Revolution be getting displacement mapping technology? It seems very likely as recent sources have said that on paper the Revolution will be two or three times as powerful as the Cube - not as powerful as the Xbox 360, and significantly less than the PS3 - despite Nintendo president Satoru Iwata commenting the system would have graphics comparable to these systems.

Displacement mapping enables higher resolution objects to be rendered with lower polygon counts, with the patents directly relating to using the technique so that a system's graphics can be computed at a comparatively low processing cost, and reducing the CPU's load while rendering 3D objects in 2D.

It's just good speculation until we hear otherwise, but these techniques could well give the Revolution an unexpected graphical boost.