If you've been having battery trouble since upgrading to Mountain Lion, there's good news: yesterday's 10.8.1 update may improve it some. Ars Technica tested it out on a MacBook Air and a retina MacBook Pro, finding that 10.8.1 brought their battery life back up by nearly two hours.
It isn't enough to make up for the three hours they lost with Mountain Lion, but it's much better than 10.8.0, so if you've been having battery life troubles, be sure to update ASAP and see if that fixes the problem. Hit the link to read more. [Ars Technica]