My understanding is that the processor speed control has become more finely tuned than before with the processor being able to throttle down to 1/4 speed instead of just 1/2 speed. This results in additional power savings. It is also more automatic now. Since it happens between one instruction and the next depending on CPU demand I don't need control over that. Properly done automatic will save more power while giving better performance than you can by manually tweaking it.
I would love to see Apple expand this with more levels of processor speed so that when the machine is just sitting there doing very little it would burn almost now power. e.g., after I've loaded a web page and reading it the processor does not need to be doing much. Activity monitor shows 3% usage. That means 97% wasted power on the CPU. Better to throttle it back and save the watts. The next step would be to also throttle back other sub systems when not in use. There is a lot of savings that could be made this way that will result in greatly extended batter life without having to come up with new more expensive batteries.
