Yes, they will. I keep hearing that their new concourse, which was originally supposed to have been completed in October 2002, should be opening in a few weeks. When Southwest moves over they will occupy all 24 gates.
Here in AUS, although Southwest is the dominant carrier, it only had 36% of the market in 2002, so AUS is not a fortress city.
At DAL, on the other hand, I believe Southwest controls a little over 90% of the market,so DAL would be a fortress city. I would imagine Southwest has more than 50% of the market in HOU, and I think I recently read that Southwest controls just over half the market at SMF, so that could count.
Does anyone know other cities where Southwest controls more than 50% of the market?
I also read an article that gave the statistics for BWI just for the month of October, and doing the math it looked like in Oct. 2002 Southwest had 46% of the market and with lots of new flights coming online soon, BWI isn't that far away from becoming a fortress city.
I think it's pretty impressive that Southwest controls more than half the market at 17 stations or 29% of all cities it serves (16 if we don't count MDW). I can't think of any other airline that could make that claim. I also note that of the 10 desinations Southwest serves in Texas, 8 are fortress cities; only AUS and SAT are not.