The moonwalk actually existed years before MJ used it.

Here is a clip of a guy doing it in 1955: http://www.youtube.com/watch?v=2VbPd2iu4bg

Later, street dancers in California incorporated the move into their style known as "popping." It was these same street dancers that taught MJ the move. And I mean these people were literally hired as teachers, not that he just saw people doing it.

But none of that takes away from what Michael accomplished as a dancer and as a singer. Clearly the man was a special talent.