Hey, I haven't tried it out yet but I found this video showing someone asking Siri to show her face and it actually works. The face speaks right along with Siri and everything!!
http://www.youtube.com/watch?v=QQfeDqNYJJ4
See, this is why I don't just throw a tracker on a layer and assume it's done it perfectly. I always go back and do frame by frame adjustments.
It's not the worst thing I've ever seen but it's obviously fake lol