I can't speak to how much an average line Captain makes since I am in the right seat. However, you need to understand that not one Airtran Captain will keep his seat. All Captain seats go to SWA pilots until Jan 2015. After 2015, if a Captain seat opens up, then some Airtran Captains may have enough seniority to bid for it.

If SWA has trained enough Captains to fill the existing seats by Jan 2015, then it might be a while before more Captain seats open up since most new aircraft purchases will be replacing 717's and 737 Classics for the foreseeable future.