Hi there.
I run Wii Fit Forum (wiifitforum dot org) and I've covered a number of stories of people using Wii Fit in various types of therapy. I was going to post direct links, but the spam protection is stopping me).
I'll be really interested to see how jamckenn's research goes. I think the Wii Fit has great scope to help, especially as it is comparatively cheap and because it can make things fun which must help, especially with children.
Paul