Each park could use a Land. Something that is new and exciting to add to off set Uni's build. If as everyone says, we are not going to have a 5th park, then increase the number of attractions, dining spots and shows to handle the increased crowds. Increase the space and filter out some of the multitude of guests throughout each park would help. This is said with the intention that staffing, maintenance and property to add on is available.
In a perfect world....
MK- After Tron opens begin a major refurb on Space Mountain
EP- Redo Journey into Imagination and bring it to a top notch attraction
HS- Bring back Jedi Training Academy
AK- Build a Jungle Book Flume ride that would rival what was Splash Mountain
Epcot - A new pavilion to explore.
Magic Kingdom - A new ride/experience in what was Stitch's Great Escape, it's a little sad that it's just sitting empty.
Hollywood Studios - A restaurant which serves breakfast (not a character meal)
Animal Kingdom - A whole new land.
MK - bring back Davy Crocket canoes
AK - the fantasy animal land that had been originally planned
HS - the original backlot tour, rebuilt in a new area, complete with the working studios, costuming, etc.
EP - add Brasil to the World Showcase
Well, not one thing but two sort of connected things. I'd like for them to have a nighttime electrical parade at MK and a nighttime show (sort of like Rivers of Light) at AK.
I know Rivers of Light was not universally liked, but I thought it was a nice little show (I really liked the music). And it was definitely better than nothing.