I predict that STL will be the next domicile. WN will continue to expand down Concourse D now (E) and STL will become for WN what AA claimed they wanted it to be for them when they acquired TW. A geographically optimal reliever hub for Chicago. This Airport is perfectly set up to be an East/West flow connecting hub. I'm actually surprised that UA or DL didn't jump on this former hub when AA made the decision to de hub it in 2003. Luckily for WN, they now are the size to do pretty much whatever they want to do there without being challenged by the big 3.