It's really hard to get excited about any of the Disney project until they actually happen. Too much time lapses between the announcement and when it opens and in that time budgets get cut, plans change and some things turn out to be better than expected and some things worse. I think Universal has the right idea of starting a project and getting it well underway before announcing it and waiting until closer to the actual opening to give more details. Yes, it can be frustrating for the "fans" watching the construction progress, but overall it eliminates a great deal of the disappointment with things that don't pan out which were promised in the original reveal.
Disney has a LONG history of announcing things that never come to pass or change in mid stream. Look at New Fantasyland. They showed a rendering, gave some details then made major changes. Some of those changes were for the better, but some set people's expectations too high and only led to disappointment and complaints. Look at the way they've built up expectations for Avatar...
If they're smart they will start building and only once it is WELL underway they should announce/confirm what they are building and only 6-12 months out give any details. Not talking about it can be better publicity than talking about it.