I know they were ValueJet and that there was a crash here in Florida.
But.......the planes are now much newer and I believe that the old fleet has been replaced.
My kids flew last week from Philadelphia and, except for having to wait on the taxiway in Philly for an hour due to heavy traffic, it was uneventful.
Just as an aside, they flew into Tampa due to gettting a much better internet rate. Tampa International is a very nice airport, easy to get into, and easy to get to WDW.
They flew back out of Orlando, and just remember that check in at departure is easy too. The entrance line to AirTran is about 100 feet from the curb side check in.
I would now use them, whereas before I wasn't sure.