So you think the iPhone and iPod Touch is going to run on Intel's Atom processor in the very near future. You might be wrong. Apple has had talks with a chip company, P.A. Semi, that makes extremely efficient processors. Founded by Dan Dobberpuhl, it has developed a 64-bit dual core processor that is 300% more efficient than its closest competitor, using only 5 to 13 watts at 2GHz. Apple has already spent $278 million on the company and it's only reasonable to suspect they should be using their products soon. Apple has been in talks with P.A. Semi before about putting their processor in Macs but Apple opted for Intel instead. According to Ars Technica "the chip sports over 25,000 clock gates so that clock pulses to different regions of the processor can be shut off dynamically to save power...All of the PA6T's major on-die components have their own separate clock and voltage domains, so that the L1, L2, DRAM controller, I/O subsystem, and each of the two cores can all be placed in different low-power states independently of one another."
As for P.A. Semi's competitors, here is the breakdown:
Atom - .8 watts at 800 MHz
VIA - .1 Watt at 500 MHz
ARM (current manufacturer of iPhone chip) - 0.25 watt multicore A9 chip at 1GHz