On Star Wars land. Disney typically has a five year development timeline from announcement to rope drop. New fantasyland was roughly five year as was cars land. Pandora/avatar expansion is on track for five years. They are going to have to clear out land already in use as well as incorporate areas like the star tours ride into the new world.
If you want an idea of the storytelling that Disney will do with this new world, I would recommend reading this article on the pandora/avatar expansion at animal kingdom. I know this is Star Wars thread but it gives an idea of the goals WDI hopes to accomplish. Remember all those articles about how you are entering a world for Star Wars land, not just a theme park? Disney is doing the same with pandora. The buzz coming out of the new pandora land is coming from people who didn't like the movie because Disney is actively trying to put you in this new world, not a recreation of the movie. Even the pamphlet mentions bringing repellent because pandora has similar insect Mosquitos to earth. Star Wars land will be the same immersive storytelling.
http://www.slashfilm.com/avatar-land-d23-expo-2015/