There was a proposal for a Horizons replacement / update that seemed to do just that. It was going to keep most of the looking back scenes, and update it to be more current (would have been funny to see Nova Cite, Mesa Verde, the Sea Castle, and Brava all represented in one scene as a looking back...) and then was going to go into space flight and into a larger space themed pavilion upstairs. There was also going to be a simulator/movie ride that I'm guessing would have used the Omnisphere. All and all, it sounded like a great update, but that'd be pretty old in the tooth by now, too.
I too would love to ride Horizons one more time with all of that 80s pragmatism, but as I said earlier in this thread... I think that was really only going to be appealing to a nerdy kid from the 80s, so I doubt there would be tons that would share in our enthusiasm
I'd honestly be happy if I knew the building was still there, even if it was turned into Buzz's space launch adventure. Losing the pavilion hurts just because of what it meant to me as a kid... In the end, though, I'm happy enough people loved the ride to upload and share their home videos with us all. It's not the same, but it is sure nice to take a 480p trip through the future of the 80s once in a while.