To hopfully clear things up for everyone...
There are two new but very different services that Disney will provide to guests starting on May 5, 2005 staying at a Disney Resort.
Disney's Magical Express is a free passenger and luggage transfer between the Orlando International Airport and your Disney Resort Hotel. It can be booked round trip or one way and is available to anyone staying at a Disney owned and operated Resort, who is flying into and or out of Orlando International Airport (regardless of airline) with there flight dates matching their resort stay dates. The transfer of your luggage from the airport directly to your resort room is included.
Disney's Resort Airline Check-In Service allows guest on select airlines to check their baggage and pick up their boarding pass for their departure flight from the lobby of their Disney Resort Hotel. This service is only available to guest flying with American Airlines, Continental Airlines, Delta (including Song,) and United Airlines (including Ted.)
The services complement each other but are completely separate of each other, as guest can use either service or both services.
My Source: Disney Reservation Center Folios Finger Tip Facts Information Database. (in otherwords, I am a Disney Reservation Agent and am getting my information directly from official sources within Disney)