I would call now. One segment of our return flight on 12/01 was cancelled. I discovered this by checking the flight #'s on the AirTran website. When I called they had already scheduled us on a later connecting flight. But who wants to sit in Atlanta for 4 hours? I was able to change the original return flight to a later one and get a few extra hours at WDW and skip the long layover. Interesting note - we wanted the later flight when we originally booked but it was unavailable. You may want to consider checking your flights on their website before you call and familiarize yourself with what is available in the event your flight has been cancelled. Then you can request to be moved to the flight that works best for you instead of taking whatever they've bumped you to. I wasn't assessed the change fee because they had changed the flights in the first place.. But inquire about the change fee before you have them rebook something else. They need to get a supervisor to override it.