Then you could include: Walt Disney World Railroad, Teacups, Dumbo, Triceratop Spin, Rock 'n' Rollercoaster, Indiana Jones Stunt Spectacular (Six Flags used to do Batman Stunt Shows), Astro Orbiter, etc. Just because Six Flags doesn't theme their rides to the level (if at all) Disney does doesn't make them cheap rides.
The suggestion that Jungle Cruise belongs at Animal Kingdom is ridiculous. The ride, as it is today, is perfectly suited for the Magic Kingdom. Perhaps if it remained the serious ride that it was intended to be (Walt wanted REAL animals) then I would agree. Carousel of Progress fits fine in Tomorrowland and would look too retro in Future World. TTA should be added to Future World.
But really, some of the quibbles about Future World or Tommorowland attractions being "todayland" would be true no matter what. They are limited to the technology and knowledge we have TODAY! Disney should rename Future World to something more appropriate. As for M:S being "todayland"...well we are still years away from landing a man on Mars (which is futuristic) so it fits in perfectly. Test Track...if it focused more on the design process in the pre-show rather than the assembly process then I would see it fitting in better.
I would say:
Finding Nemo: Studios (it could replace Beauty and the Beast)
Beauty and the beast: Magic Kingdom is more fitting
Voyage of the Little Mermaid: Magic Kingdom is more fitting
Monsters Inc: I agree it should be at the Studios