My 4 cents:
Animal Kingdom: The Animal Kingdom has far and away the best possiblities for expansion. With animals playing large parts in many disney movies, a celebration of live animals that can be found in Disney movies would be the best way to go. I love seeing little kids in the Pangani Forest point out the meerkats and call them Timon. They recognize them through Disney movies and as Disney attempts to promote animal health, husbandry and awareness they have to find ways that the World's Youth can freely associate with it. I know they have been in communication with the Chinese government in attempts to acquire Giant Pandas and Asian Elephants. If Disney would be able to coreograph the release of an animated movie with a new Asian Animal Expedition attraction the results could be a tremendous boom in animal conservation.
I personally love this idea. Especially if they also finally built a long-overdue Jungle Book ride. I really wish they'd make a serious ride for one of the best loved Disney movies (the same also applies for Aladdin and Beauty and the Beast), why they have left these for so long and have instead built rides based on Stitch, I have no idea.