I would make it blend in and theme it to Walt Disney World. If it is going to be the Walt Disney World airport is should have a Walt Disney World theme to it. I don’t know how I would exactly do this but i’m sure if the imagineers think for once they could do something awesome, LOL! I would probably make it a regular airport but with the Disney feel. Have Mickey’s and various Disney characters, maybe even a meet and greet before heading on your flight. I would also have a dedicated bus area for Disney transportation. Be busses to either your hotel or Disney park if you want. (I know it’s unlikely but a people mover or monorail would be great.) I would also make a dedicated rental car facility away from the airport.
TL;DR: Disney themed airport with Mickeys, Meet and Greets, Have a great flight!