From this Eurogamer news article:

Microsoft has boasted selling over 2 million copies of Gears of War 2 during its opening weekend.

Furthermore, more than 1.5 million Xbox Live account holders played the game, according to Major Nelson – clocking up a record 15 million gameplay hours between them.

15 million hours is a lot of CPU time on the triple-core Xenon that runs a 360; a lot of processor power.

There might not be a cognitive surplus, but here’s a thought: what happens if, as a kind of “CPU-tax”, you require manufacturers to include an “extra” CPU or core in certain kinds of products – entertainment products, set-top boxes, consoles, PVRs, that kind of thing. That CPU is self-contained – processor memory, the lot – and devoted to running something like Folding@Home in the background, or whatever the next massive philanthropic grid-computing project the world needs to run is. Maybe you specify specific charity interests you have, so you can contribute to projects you care more about.

And then you have 15 million hours of 3 cores running Gears of War 2, and 15 million hours of protein-folding. Seems like a good trade-off to me.