Mother of sweet things! I saw this on Reddit's /r/wow community a few days ago and realized that I'm kind of a slacker when it comes to my own forum signatures (which is apparently the whole purpose of the project). Thovald, the player responsible for the video, wrote that he did it in 3D Studio Max and didn't actually change the female troll model itself. The big difference is an increased polygon count for the robes and (I would assume) the graphics of the fire spell being cast. It reminded me more than a bit of the perennial favorite Blind, and it's all the more amazing that Thovald is apparently self-taught.
We know that Blizzard is working on an update for character models, but it's pretty cool to see what players can do with them in the meantime. They might be old, but as Thovald noted, they're still a surprisingly expressive bunch.