On my vaio i have some improvements with powertop's tunables, but i don't know how to get those changes permanent.
I can go from ~17W to ~14W, not bad. But at the moment I have to open powertop, go to Tunables tab and toggle every switch marked with BAD.
In particular I had two unused peripheals draining ~400 mW each, (fingerprint reader and ethernet card) After activating the PM of those peripheals via powertop, now the drain 0mW..
another remarbable thing that i spotted in powertop is that the display backlight is reported three times (draining ~800 mW each time). Maybe it's just a powertop problem, but I think I'll make a natty live usb to see if it was the same.