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.
The shoes though appear to be a fresh concept.
Dance that is exposed in the mainstream is a very thin slice of what is actually out there. Nor is it usually the "best".
I will confess that his moonwalk is pretty damn good though.
And while I will say that there are a large number of people that dance "better" and certainly more technical than MJ...
I have never seen anyone TOUCH his moonwalk. As far as I am concerned he was the greatest there ever was at that move by far.