No offense, but ugh. Cities are noisy enough anyway; assuming that the music accompanies the dancing figure, this would simply add to the cacophony. And while it may be more effective than a standard traffic light when it's a novelty, I suspect that before too long you'd see people going back to their old behaviors.
Unless I'm remembering incorrectly (always a possibility), Indianapolis tried something similar in the Massachusetts Avenue arts district: an art installation depicting an outlined, stylized female figure. When the light was green, she would dance (basically just swaying side to side); wen the light was red, she would put one hand behind her back and tap her foot. Not exactly the same as the Youtube video, I know (and watching her stand and tap her foot wasn't terribly entertaining, although it did send a clear message), but it didn't work. The installations are still there at a couple of street corners, but now she just sways full-time.