I would rather see the attention spent on current parks than opening a new park... Currently I think AK is getting enough with a much needed boost (new land, nightime experiences etc) that will make it a much better park without sacrificing its special appeal.
Next up I would like to see 'LOVE' given to Hollywood... I think a Stars Wars expansion will be a natural fit here, just expand upon the existing (gift shop) area... add in a couple of new rides... a seedy space bar restaurant/bar would be fun.
I think Epcot could be made better by just retheming the areas it has and does not use... what about a tech sponser like Apple or MicroSoft putting something into innovations?
What are the rumors I have heard about a Sea WOrld type place? With the waning love for captive sea creatures (Blackfish anyone) this might not be the smartest move...