I chanced upon an article in the newspaper over the weekend about this:
http://www.usatoday.com/tech/gaming/2008-02-08-wiihabilitations-hospitals_N.htm Hospitals are now using the Nintendo Wii as a form of rehabilitation for patients requiring physical therapy. I imagine that with the release Wii Fit that this trend will only become more popular.
Now if they would only invest in this kind of PT at my workplace...