Yes, it's all speculation until approved/announced/actually being build.
Given the IP obsessive nature of the company at this time, what does everything think could be used? Wreck It Ralph might still be used (either as a video game or using Hero's Duty/Sugar Rush/Fix It Felix Jr) for the "new" attraction. Other options might be: Tron, Big Hero Six, GotG (or maybe another Marvel property, maybe something based on SHIELD?), Stitch, Star Wars (seems unlikely they'd put it in two parks), Wall-E. The Incredibles?
Tomorrowland could be an option, but given the reception, doesn't seem plausible. Same with other "bombs" like John Carter, Treasure Planet, or The Black Hole. I'm skeptical they would use Miles from Tomorrowland as an IP for a major project given the relatively obscurity of the property.
Computers:
1. Wreck-it Ralph
- Ralph v. Fix-it Felix
- Candy Rush fast ride (could be simulated)
- Hero's Duty Bug Crusher
- Light Cycle
- Any version of black light games, could be several... build it like Toy Story Mania
Space:
1. Wall-E
2. Stitch in Space
3. Muppets: Pigs in Space
4. Miles from Tomorrowland (either a kiddie ride, or, a really good innovative family ride where the IP doesn't matter too much)
5. Star Wars (Frozen is in three different parks, so, hey, why not SW?)
6. Mission to Mars (hey, this time, it's not some far off pipe dream, only this time, add your favorite IP character who's a tourist to Mars with you)
7. Flight of the Navigator
Supers:
1. Incredibles
2. Big Hero 6
3. SHIELD (hunting bad inhumans)
4. The Inhumans
5. Sky High
Supers in Space:
1. GotG
2. Ms. Marvel
Science!
1. Self-driving Cars demonstration, but by the cars from Cars. As the demo gets underway, the cars hear a favorite song on the radio and start dancing like Luigi's Cars in Cars Land.
2. Goofy's Time Traveling Machine (or any other favored IP who stumble upon and in a time travel machine with lots of stops in the future.
3. Honey! I Shrunk the Kids!
4. The Rocketeer
5. Cross Dimensions: Professor Honeydo's experiment goes haywire and you transverse multiple dimensions going to the worlds of Monsters Inc., Cars, Zootopia, Wonderland, Mickey's Cartoon World, Wreck-it Ralph, Star Wars, etc...