It's just a reference to the style in which roadside attractions, circus show performers, and fortune tellers are billed. The Amazing Randi was the man's stage name so it comes together for a clever title.
I see the cleverness in the title; I also see that it's most obvious, and literal, interpretation is one of putting down his skepticism. Before reading the article, I thought it was going to be about how James Randi is too skeptical.
