To those that have implied that this is a marketing ploy to get you to buy an iPhone 5, don't worry. It isn't. :-)
My iPhone 5 battery life is also crappy. Can't get through half a day. It's not a ploy. It's a technical problem. We have iPad 2, iPad 3, iPhone 4, iPhone 4s, and now iPhone 5, and they're ALL having this problem. All apps are closed, diagnostic data isn't being sent to Apple (which played a big role in the problem with battery life in the 4.0 and 5.0 iOS releases) and everything else is as it should be.
Where I would get 1.5 days of use on the 4s with 5.X, I'm getting less than half a day with the iPhone 5 and iOS6.
Please fix this Apple. Please. :-)