Adventurer's Club Dinner Show. They need another dinner show on property.
Magician Mansion. Interactive magic club with in house and guest magicians performing.
Expand and update Disney Quest. More unique Disney games, also have a tower with regular arcade games.
Each floor could represent a different decade... pinball and antique machines on the ground floor.
Ink and Paint Club. All Toon revue! This has been mentioned before, an all animation themed club.
Uncle Scrooge's Adventures. Large pyramid building allowing guests to engage in different activities in an effort to find a rare treasure.
Possibly make a Disney Legoland and expand the store. Of course this would be invovling a third party but Legos are really cool.
Star Wars Cantina Bar. Some of us would never leave. Well, at least we wouldn't want to.
Turn the area into Adventure Island and install a ride showing the 'history' of the Island while taking guests on their own adventure.
Heck, they could really do ANYTHING they wanted with the area that would be more interesting than a hot dog stand and a bar. People go to Disney for Disney's theming and atmosphere, not third party bars. Its just laziness and thats really too bad.