Source: http://gizmodo.com/5620509/ibms-new-processors-go-comatose
IBM's adding a new lower-low-power option to future Power processors that's one step beyond its current nap, sleep and heavy sleep options—the ability to put the processor into "deep sleep". It'll feel very refreshed in the morning.
Cutting power to the processor by a bigger margin than before, the planned new option will allow future chips to draw "almost no power" when not being heavily used, although putting your processor into this new persistent vegetative state has its drawbacks—there'll be a 10-20 millisecond wake up time to bring it around again. [PC World]