I like the idea of the western backlot theme. I am picturing something like a much nicer version of Wild West City in New Jersey, where perhaps the streets would close down every so often as a "show" is performed in the streets...horses, gunfights, etc. That might be a bit much for Disney, but it would be cool.
Part of me doesn't mind that some parks are 1/2 day parks, as I always break my day into thirds (park in the morning, swimming mid-day, and park at night), but the bigger problem is that there isn't enough there to bring me back a second time during the trip. If there were five GREAT rides, I would want to hit the park a few times during the trip, but there isn't.
I think that a major appeal to Magic Kingdom is the mix of thrill rides (Thunder Mountain, Space Mountain, Splash Mountain) and rides that you just sit in and passively go through (Small World, Pirates, etc.). That ensures that it is not only fun for the whole family, but also that you can come back multiple times and basically "theme" your visit (all thrill rides, all laid back rides, etc.). On top of that, the parents and kids can separate, with each group tailoring the day to their own interests....You can't really do that at Animal Kingdom and Hollywood Studios. Simply stated, there aren't enough rides. And with Epcot, there are enough of the passive rides, and not enough of the thrill rides.
From my seat, it seems like DHS, Animal Kingdom and Epcot are all about 6-8 rides away from being perfect, not only for the entire family, but for an entire day trip. In each park, I'd put in three rides that would appeal to teens, and three Small World (or better yet, Pirates of the Caribbean) type rides that would appeal to everyone.
They are close, but not there yet. I know it costs money, but they would get it back quickly if they would bite the bullet and give the people what they want.