Yesterday I was listening to a fun episode of the Unofficial Guide's Disney Dish with Jim Hill podcast that was all about Disney's Hollywood Studios. Host Len Testa and super-Disney know-it-all Jim Hill spent over an hour going over the history and interesting backstories of the origins of the Studios and there was one tidbit of information that I wanted to share with you all.
When Imagineers were planning the Disney-MGM Studios, they were coming off a recently completed Epcot park that was, well, enormous. Epcot is a giant park and dwarfs the Magic Kingdom in terms of sheer size. While that immense space has its benefits, Imagineers wanted to create something smaller and more manageable for Walt Disney World's third theme park.
Executive Vice President of Walt Disney Imagineering Bob Weiss had heard a lot of the complaints about the size of Epcot, so they addressed it by going back to the Disneyland roots. Bob figured out the length of Main Street USA in Disneyland from underneath the train station to Sleeping Beauty's castle and made that the distance at the Disney-MGM Studios from the turnstiles to the Great Movie Ride.

In fact, the scale of the buildings at the Studios is the same scale as the buildings on Main Street USA in Disneyland. All of this was a reaction to what happened in Epcot and the complaints Disney received from it.
I encourage all of you to check out Len and Jim's podcast and enjoy this and other fun tidbits (and be sure to complain to Len that he needs more time in the Studios!).