@antonywu : The firmware upgrade they are talking about is to enable the Power nap feature, not to improve battery life.
On my mid-2010 MacBook Pro, Mountain Lion has actually INCREASED my battery life, almost doubled it from Lion. Whatever is affecting the majority of people on this thread luckily isn't affecting me, and since ML is smarter about when to switch from integrated to discrete graphics, I'm seeing better battery life. I'm getting close to 6 hours if I try to keep away from any apps that force it to the discrete graphics (Chrome, Transmit, Espresso are some of the apps that force it to discrete, so I keep those closed when possible). My battery has 1061 cycles on it and a health of 88% from new.
Also, I use both Mail and Dropbox, a couple of the possible culprits cited in earlier posts in this thread, so I don't think those are the problem.
I hope Apple is able to solve this quickly for you folks that are seeing issues, because I think when you finally get back to "normal" you will actually see a little better battery life in normal usage compared to Lion.
EDIT: by the way, I'm at 80% and 5:03 left right now, for comparison. I have Safari, Mail, Reeder, Tweetbot Alpha and Pages running right now, along with a bunch of menu bar items like Meterologist, Dropbox, Evernote helper, 1Password helper. gfxCardStatus, Caffeine.
Oh, one other note: I try to keep the widgets on the Dashboard from running when I'm on battery too... I issue a "killall Dock" from Terminal that will shut all the widgets off. I noticed back when running Lion that the Dashboard widgets I run tended to use more battery.
Message was edited by: corsa