Apple has officially confirmed that several bugs in iOS 5 are negatively affecting battery life.
In their statement they acknowledge the problem and said that they will "release a software update to address those [bugs] in a few weeks." Apple haven't provided any information on the specifics of the bugs, nor have they offered any temporary work arounds or advice for those experiencing poor battery life.
Shortly after their statement, Apple released a beta build of iOS 5.0.1 to developers. According to its changelog, this release fixes bugs relating to battery life and iCloud document syncing, improves voice recognition for Australians and re-enables multitasking gestures on the original iPad.