Not to sound too informercial here, but one fact in this tough market is when you show up for your interview, you'd best be VERY ready and very well prepped.
There are several interview preparation courses out there....Cage Consulting, RWB Consulting (Rob "Mozam" Beeks), and Emerald Coast Interview Consulting (yeah...thats me).
If you get the call from one of these companies, get some help! I've got my business banner up, but RWB is THE guy out there for SWA wannabes. I have had a great track record at JB and FedEx. I don't know anyone who specializes in AirTran interviews, but Cage consulting for years was a good "general" source of interview prep--they might be of help.
Both FedEx and AirTran have simulator evaluations. I DIDN'T go to a specific sim check prep course, but I also interviewed pre 9/11. If I got called for an interview in this environment, I'd probably write off the 300-500 bucks and knock the rust off if I didn't already have access to some kind of heavy turbojet simulator.
It is true things are tough right now...but its also true that when you get called in, the airline WANTS to hire you. They didn't spend all this time and money just to fly you in and crush your ego. One way of looking at it is the an airline hires xx percent of whoever they interview....all you have to do is make sure you are in that percentile! In the fighter business, there is an expression that goes "Don't be a LIMFAC". (A LIMFAC is a "limiting factor", something that keeps your mission from being as successful as possible. It can be aircraft, avionics, weather...or..well..YOU). You can't control all the variables in this tough industry, but you can at least be as qualified, well informed, and ready as you can be when its your turn at the plate.