I don't even agree with the buildings looking dated. Mission:Space building looking dated? Really? The jumping fountains and the backwards water at Imagination dated? The rushing water aside of The Living Seas dated? The entire Spaceship Earth with it's revolutionary way of funneling off rain dated? Test Track with the outside track going over the waiting entrance dated? The fountain and its show dated? The ever changing exhibits inside Communicore, er, Innoventions dated? OK, I have to give you The Land because, well, it's land and you really can't change that too much - the layers representing the earth's crust on the outside of the building really can't change for about a million years.
No, I don't think Future World is dated. Maybe if you've been there often enough, you might be getting tired of seeing the same old buildings but they are not dated, in my opinion.