Originally, a Carousel Theatre called "Meet the World" was to go in Japan. It was built, the show building was built, but it didn`t fit (no joke). Since EPCOT had overrun it`s budget by 100% they couldn`t afford to rebuild. The show did open at Tokyo Disneyland in 1983.
Next was to be a Circlevision 360 simulator of a ride on the bullet train, using the empty Carousel Theatre show space. Jim Hill recently ran a story on this.
In the early 90`s Mount Fuji was proposed - a rollercoaster. Fujifilm even offered to be sponsors and foot the entire bill. However, Eastman Kodak wern`t best pleased Fuji might be in the park (and able to sell merchandise) so the deal fell through. The Mt Fuji Rollercoaster was to be half of a pavilion expansion - the Ginza district (think Bladerunner) would had been the other half.