Running marathons frequently (marathon maniacs and the 50 states club)

With growth of marathon maniacs and the 50 states club, more people are running marathons frequently. Some runners only have a few weeks between each race, while others are running two marathons a week. I was asked for my advice on how to approach frequent marathon running, and so I created a new page http://fellrnr.com/wiki/Running_frequent_marathons