On your way to Disney World, you can use the DME luggage tags for any airline. Your bags will be transferred to your resort automatically.
The participating airline list only applies to your trip home. If you're flying domestically on a participating airline, you can check your luggage at your resort and receive your boarding passes. Your bags are checked through to your final destination. If you're not flying on a participating airline or are flying internationally, the driver will place your bags in the luggage compartment of the bus, and then return them to you when you reach the airport. You'll need to check in and check your bags with the airline.
The current participating airlines are American, Continental, Delta (including Song), JetBlue, Northwest, and United (including TED).