Delta didn't need the AirTran feed into ATL and quite possibly needed a LCC to keep the appearance that there is competition in Atlanta. It's not like SWA has done anything but shrink the AirTran footprint anyway.

JFK is another story. JetBlue offers an instant domestic feed as opposed to LGA, where all the feed is now. Trust RA at your peril. The 717s were a sweetheart deal, but don't expect Delta to look the other way if someone else makes a play to grow in JFK.

Anyway, JetBlue will probably be bought by someone else before SWA has finished choking down the remmnants of AirTran.