I think Disney needs to put the big ax to this project immediately and stay with projects not associated to James Cameron. I know that Disney Execs can be pretty picky and have their own agenda, but this land seems doomed because of this guy. I can imagine him being a micro-manager of epic proportions on this type of project. They need to stick with their own films and do what they do best, build immense experiences around their product/films and not be derailed by outside timelines and productions.
Disney has shown with Carsland that with whatever theme or movie they work with, they can hit a home run. The big if is how much do they spend on their projects and do they go the extra yard. With one more big ego in the picture with this project, I feel that it's going to be a massive tease leading to a massive let down if it ever happens.