There is a discussion of this issue -- as well as Disney's (completely bogus) response -- on the DisneyLies.com blog:

http://www.disneylies.com/blog/2008/07/02-walle-and-copyright-infringement/

There is a band called Edison Square that does nothing but songs about Disney. Nothing about them on this site, though.

I agree with Andrew Mayne's comment. Knockoffs of popular tricks are thrown onto the market all the time. Also, magicians use Web sites like mallusionist.com to try and trap people online who are searching for magic exposure, because they have no way to stop the "leak" of secrets.