This MIGHT (and it's only a guess on my part, based on some early observations) be related to the reduced cell reception some of us have noticed. If the signal is reduced, then that phone could be "trying harder" to maintain that link, especially if you're in a spotty area to begin with. This would match the increased temp, and shorter battery life.
Once again, I stress, this is a POSSIBLE GUESS on my part, not fact, not even hypothesis yet. We'll need to gather more data to be sure.
Mine did the exact same thing after the last upgrade as though something was constantly running in the background. The way I finally got to resolve the issue was to do a restore not to be confused with a reboot. Haven't had the battery issue since.