Southwest recently added a new early boarding fee called "upgraded boarding" and added fees on overweight baggage. They also admit that a no-show fee is in the works for the near future.
Nothing too serious yet, but admittedly Southwest has struggled compared to other airlines who have found ancillary fees to be the path to profitability.
In recent months, Southwest fares have been highly competitive beating out other airlines where they hadn't been in quite some time. Is it an attempt to build customer loyalty before adding more fees? Or the result of collecting a little more in optional services? We shall see.
For now, it is a great time to use Southwest, particularly with no bag fees for the first two bags and no change fees.
Sources: http://www.reuters.com/article/2012/12/17/uk-southwestair-fees-idUSLNE8BD01O20121217
http://www.southwest.com/html/customer-service/travel-fees.html
