I've already given my thoughts as to what my vision for Tomorrowland would be, but here's a revision IF they were to go this route of not a complete overhaul, then at the BARE MINIMUM this needs to happen:
1. New attractions in Buzz Lightyear and Star Tours buildings.
2. Demolish Carousel theatre and put a new attraction in its place.
3. Tomorrowland theater needs something than what it is currently. Literally anything. I would vote a new counter service area and make the Pizza Planet space the new queue area for whatever they replace the Carousel theater with. Though that could cause some congestion next to Space Mountain's entrance, but then that's more reason for them to put the escalators back where they were.
4. Astro Orbiter anywhere else, but the front of the land. New entrance entirely.
5. PeopleMover. I don't know how, but we all know that fans, including us, won't be happy without a new PeopleMover. Kinetic energy is needed so badly in this land. Suppose where the new loading platform for the PeopleMover goes where the Carousel theater is today.
6. Remove all color schemes of Tomorrowland 1998. A blue, white, and silver future is always preferable.
Again, this sounds like a lot, but the only things demoed were the Carousel theatre, Pizza Planet restaurant, Astro Orbiter, and the old PeopleMover tracks. It would be perfectly easy to do these in phases, too. I doubt even Disney will do even half the things I mentioned above, but it's worth thinking about anyway.