From mousesavers.com:
Walt Disney World Resort is now offering a service called Disney's Magical Express that includes complimentary airport shuttle, luggage delivery and airline check-in (for selected airlines*) for Disney hotel guests.**
On May 5, 2005 Disney's Magical Express began allowing all guests staying at Disney owned-and-operated resorts to check their bags at their hometown airport, bypass baggage claim at Orlando International Airport (MCO) and board motor coaches to the Walt Disney World Resort. The idea is that your bags will "magically" appear in your room after check-in.
Disney's Magical Express service is intended to make guests' return to MCO hassle-free as well, offering motor coach transportation back to the airport. In addition, the new system allows guests on some domestic flights* to check their luggage and receive a boarding pass before departing their Disney hotel. They can check their luggage at the Resort Airline Check-in Desk and then enjoy the last day of their stay.
The obvious advantages of Disney's Magical Express are its supposed convenience, seamlessness and the fact that it is FREE. However, you should be aware that it is shared bus service, with Magical Express buses each visiting up to 4 resorts to drop off passengers, and therefore your transfer will almost certainly take longer than using a rental car or towncar service. Depending on how much you value your precious vacation time vs. the cost savings, Magical Express may or may not be for you.
*Participating airlines for the resort check-in/boarding pass service are American, Continental, Delta/Song and United/Ted. As of 7/25/05, JetBlue will become a participating airline.
**Disney's Magical Express is available only to guests staying at the official hotels owned and operated by Disney. The Walt Disney World Swan and Dolphin hotels, the seven Downtown Disney hotels and Shades of Green are NOT included.