Anecdotally, I appear to get better battery life with Windows (and some vendor-specific additions) than with Ubuntu on my laptop.<p>It's great to hear this is an active area of development, as it's probably the biggest remaining factor in me choosing host OS.
Excellent. I'm still on 11.04 on the laptop atm. I installed 11.10 on the HTPC and it didn't seem to provide anything new that was especially useful. I think I'll give 12.04 a try in July after it's had a few months to bed in.
I'm using an old Thinkpad x41 running Lubuntu 11.10. It has a new third party battery, 6 cell...the batt is now more than 1 year old now. I get well over 3 hours on a full charge. I'm pleased with this. Would be happy to put a future ubuntu on a future MacBook Air and get 6 hours of battery. That's about the only thing that might pry this x41 out of my hands.
I've been playing with the 3.2 kernels from the Ubuntu kernel PPA and there's a dramatic increase in battery life for me. I go from ~3.5 hours to ~6-6.5 on the same hardware. (It's a bit unstable though... I've had a couple of crash issues. But it's still a development kernel so that's to be expected.)
Hopefully this is true, I bought a Macbook because my older laptop with a new battery and Ubuntu lasted for less then an hour fully charged. There didn't seem to be any native power-management tools and all the solutions seemed overly complicated and hacky.