Around the fifth minute of the http://www.gametrailers.com/video/e3-2011-elder-scrolls/714852, we can see the character breathing fire at the frost dragon and the dragon... dodging it?
I really hope it's not just a spectacular coincidence and certainly not exclusive to dragons. It's about time NPCs learned some self-preservation - it kinda makes sense to back the heck away when the psychopath in front of you is about to incenerate your face with their breath... right?