Here's your solution. Create an obvious distinction between Tomorrowland and Future World. A definitive line can be established based on existing infrastructure and attractions. Both areas need significant work so now is as good a time as any to establish what's needed.
Tomorrowland: This will be a fantasy view of the future, grounded in intellectual property.
Future World: This will be a realistic view of the future, grounded in original concepts, history and realistic visions of the future and/or modern technologies.
This would result in wholesale changes to both locations. What I'd love to see would be a new Space Mountain building inside Epcot, near Mission: SPACE (possibly demolishing Wonders of Life). I'd also like to see an upgraded Carousel of Progress in Future World as well. If it's part of a new Horizons concept, even better. The reality is that Space Mountain in it's current Magic Kingdom state needs a new track and entirely new effects. Why not use this as an opportunity to build a new one in Epcot while running promotions on the current one before it goes away?
I want to see a peoplemover in Future World and I'd love to see Nemo removed in favor of a new Seas pavilion (or perhaps even a new concept their entirely as that's a better fit for Animal Kingdom at this point). As for Imagination, there were rumors that Dreamfinder and Figment would find their way to Tomorrowland as well as meet and greet characters. I wouldn't oppose this, but could see a logical fit in either land.
I could also see Future World being renamed to Discoveryland to better represent past, present and future.