Well I think this quote is a tell tell sign:
"We would not have made money in the fourth quarter if not for fuel-hedging gains," the Fort Worth
Star-Telegram (free registration) quotes Kelly as saying on the conference call. Kelly said the airline's fuel hedges boosted the carrier's bottom line by $300 million in the quarter.
Southwest doesn't have the competative advantage to the extent it once did. Previously they were the lowest cost carrier, could swoop in to almost any city, USA and undercut whoever and make an easy buck while growing. With a saturated domestic market, no real international flying to speak of and lower cost carriers who have more ammenities things are different now. Also the majors/legacies drastically reduced their operating costs. The saving grace of Southwest right now is its fuel hedges and lower debt. Even with the lower debt it is a bad sign that without fuel hedges they would have lost money last quarter.
On a separate note the pilots at southwest are very reminiscent of the pilots of United back in 2000, very outspoken about how they are paid more than everybody else and thinking they are invinceable. Time will tell. For right now though their eggs are all in one basket and the bottom of that basket is now made of wet tissue paper.