Rush mentioned today that the stage was designed by the same guy who designed performance stages for Brittney Spears.
Quite literally. He cited an article on the Washington Post and mentioned the guy's name, though I can't remember it right now.
The Hitler references are a bit weak, IMO. I hate the guy almost as much as I hate McCain, but he ain't Hitler. That stage looks nothing like Hitler's stage, either. Hitler's amphitheatre in the provided picture is an imposing structure several hundred meters long, representing the strength of the reich, not necessarily that of Hitler himself. Obama's stage looks like the cheap off-Broadway styrofoam prop that it is, and sits in a small corner of a football field, designed to put focus on Obama, not on the aparatus he wishes to pilot as President.