My 2 cents worth.....
I believe UPS will be around for a very, very long time.
At some point SWA is going to start paying the same price for gas as all the others....they can't hedge forever. They will be renewing their contracts in the next few years, pilots, attendants and mechs all coming due soon.
The passenger industry is one of the few industries where they are selling their product for less than it cost to produce. UPS and FDX don't do this.