The only problem with fixing Epcot is that there's so many things to fix
AK is pretty much set after Pandora. They just need to fix Dinoland and Everest. DHS will also pretty much be set after SWL and the Pixar expansion - just some general plussing/revamps and maybe one C/D family dark ride on Sunset Blvd to complement ToT and RnRC.
But Epcot just has so much to do in order to become a top-notch park once again (as much as Universal Studios Florida did in 2008-2009, actually):
Imagination pavilion (has no vision/ambition at this point)
the empty Wonders of Life pavilion
the empty Odyssey Restaurant
Lack of rides on the right side of World Showcase (opposite Frozen/Three Caballeros)
Adding more Three Caballeros AAs to the Mexico ride (just wishful thinking)
Lack of updates for World Showcase films (China, France, Canada)
Innoventions
Ellen's Energy Adventure
Spaceship Earth finale
Mission - SPACE (more interactivity, randomized sequences, possible expansion to be more ambitious, etc)
I definitely think Epcot is on the list next, because of how much AK and DHS are getting. They'll be far more appealing in 3-4 yrs compared to Epcot. By 2019/2020, it'll most likely be the Orlando area park you skip or do a half-day at.
Hopefully you're right, and TDO decides to get started on a Future World overhaul!