Also, AirTran's initial flights fit in nicely with Southwest's current schedule. (I'm looking at Southwest's nonstops only).
Right now, Southwest has nonstop departures out of BWI at 7:50 a.m., 11:10 a.m., 5:55 p.m. and 8:35 p.m. AirTran's 3:35 p.m. departure fills in a gap between Southwest's 11:10 a.m. and 5:55 p.m. departures.
Out of MCO, Southwest has nonstop departures to BWI at 8:40 a.m., 10:05 a.m., 11:30 a.m., and 5:35 p.m., so AirTran's 12:45 p.m. departure also allows for more flexibility for people flying MCO-BWI.
Later on in March, when AirTran adds it's second roundtrip in that City pair, their 7:30 a.m. departure will compete somewhat with Southwest's 7:50 a.m. departure, but AirTran can advertise that they have the first departure of the day.
And from MCO, AirTran's 7:35 p.m. departure back to BWI will be the last flight of the day, a full 2 hours after Southwest's last nonstop flight in that direction, so I think Southwest's and AirTran's schedules on that route compliment each other very nicely. I hope AirTran does well on this route and I think there's plenty of passengers for both AirTran and Southwest.