Wal-Mart seems to be taking over the world! Or at least that part of the world that controls retailing in 21st-century America. With its sales over $256 billion in fiscal 2004, Wal-Mart is within striking distance of dominating a 10 percent share of the total $2.9 trillion U.S. retail market, excluding motor vehicles and parts. When it reaches this pinnacle, and I suspect it will unless the gov…