Well, Airtran said that the new 717 would replace the 737 first. That increases commonality somewhat. But Airtran has not had that opportunity, since they have done some expansion, and used the new planes for that. So now maybe they are starting to scrap the 737s. Good thing, I say. While I love the 737-200, they are inefficient, and their frames are getting stressed beyond original intentions. I hate to see them go, but it is time to usher in the new age of aviation.