Linux-based UI?

"The instruction set a CPU uses hardly affects power use at all."

This is not true. x86 wastes a 'huge' amount of power just decoding the absurdly complex
instruction format.

When compared to most embedded ARMs and MIPS SoCs, the Atoms and VIA chips show a rather poor
performance/power factor.

The reason they are popular is because they target the area where users are going to want to
start running 'normal' apps. And that, to them, means x86/windows.