My battery life seems to last as long as it did on Snow Leopard, too.
As for actual on-battery use - yes, the battery life is noticeably improved over Lion.
On Lion at least I noticed that if I left my USB HD in, and closed the lid on battery it killed it, every time. There was an Apple Support thread confirming that.
I've got some time next week to look at it, and intend to get to the bottom of it. It's annoying to not be able to carry around a sleeping laptop for a day without it dying.
I wonder if this same issue would crop up with the Amazon Cloud Drive.... It's not much more than a CIFS/NFS mount.