I've been testing out my MBP's battery life for a while now. Gained about an hour over Mountain Lion with approximately the same kind of usage. Looks like those battery optimisations weren't all fluff.
I'd say that's about right.. been using battery power the last hour, web browsing, opening closing and testing apps, some light photoshop and I just dropped 2 percent as I started typing this post..
P.S- and my keyboard backlight has been on as well..