I thought about this as soon as Disney bought out Marvel. Does Universal pay out royalties to Disney now for using Marvel for IofA? Is there a date the contract "expires" and Disney can choose not to renew it causing Universal to scrap all references to Marvel? That would so brutal to Universal if it happens but I wouldn't mind seeing Disney take a crack at a Marvel comics theme area!
From what I understand, part of the deal with Universal is that they can continue to use the Marvel characters that they're already using...
for as long as they continue to use them.
In other words, their contract doesn't expire until they stop using the characters. So long as they continue to use the characters, their contract is infinite.
I believe this is why Disney is primarily focussing on the Avengers line, while Universal continues to use Spiderman and the X-men. Can't recall if I've seen any Disney Hulk products...
As for the original question...
I can't really say, as I'd have SO much more information than I do now about markets and budget and all sorts of other things. Whatever I'd imagine myself doing now, it'd likely have no relation to what I'd do in real life.
That said, I'm actually looking forward to Avatarland, as I think the ecology theme fits well with Animal Kingdom's mission, and that park is desperately in need of some nighttime-friendly attractions. I don't care about the movie, but I think glowing alien plants will be lovely and a boat ride attraction will fill a hole in the park's current line up.
An expansion of the Star Wars area in Hollywood Studios would be awesome, and is probably a safe project given the popularity of the weekends.
Epcot needs
something, but I doubt it'll be a new country. As far as I'm aware, there are no countries currently interested in funding or sponsoring a new pavilion. It's a bit of a rough economic climate out there, and it's hard enough for foreign leaders to justify sponsoring the Olympics to the voting public, much less a frivolity in Disney World that will suck money out of your budget year after year, and won't do much, if anything, to increase tourism. Disney's best bet would be pitching the project to private investors and corporations (anyone wanna see a Pavilion for Sweden, sponsored by IKEA?

), but I can understand why it's on the back burner for now.
If I was running things, I
think I'd focus on completing New Fantasyland and the assorted refurbishments, smoothing out the bumps in the Next Gen, figuring out what all this new data means and how it can be used, moving ahead with Animal Kingdom and Hollywood Studios and spiffing up Downtown Disney, and leave Epcot at the bottom of the list. It's doing fine for the moment, just hosting regular festivals throughout the year.
But, as I said above, I don't have even a fraction of the intel needed to have an informed opinion on any of this.