My most recent x86_64 motherboard has lots of passive heat sinks and tubing. It looks like a roller coaster. A reduced power CPU would be welcome...especially for embedded work where power and cooling are an issue.
Thinking Small: New Intel Architecture Champions Sub 1 Watt x86
http://www.dailytech.com/Thinking+Small+New+Intel+Architecture+Champions+Sub+1+Watt+x86/article10930.htm
...the “Atom” chip. And I’m sure that AMD will produce something competitive before long. We’ll also see fans disappearing from more of the fancy video cards (multi-CPU boards for direct rendering) pretty soon.
The young folks and I will probably run some tests to see how much power cheap SATA drives really use over a day. I’m guessing that they don’t use much when configured to land between use periods.