Not sure if this has been reported, but I’ve noticed that since the Flame and Frost update, I could move my character’s head side to side with my mouse camera using certain weapons. At first I thought it was a new feature, but then I noticed I could do the same with other people’s characters that are on screen with mine. Very entertaining to see so I made a video to show it.
http://youtu.be/dmRofY6uv4s