Welp, bases on this thread I'm just gonna go ahead and advocate that WDW just craters DHS and plants a garden over it. According to the majority of posts, there is NO WAY that this will EVER be awesome, it will take 15 years to build, and the "only" two new rides will probably be a carny level Tunnel of Love and a Tilt-a-whirl painted like an X-Wing.
Sheesh, people. Some of us (and most of you) have been waiting for something like this for almost 40 years.
Enjoy the moment.
EDIT: Oh, and by the way - I'm not saying "don't talk about it." Have fun, speculate away! I'm just saying that the "Disney will blow this, too" attitude is a little over the top.
Here's my take - Harry Potter freaked the crap out of Disney, and they know it. They know they need a game changer, and this is it. They're gonna go all out. I'll bet there's a three year timeline, and I'll bet the plans are to make it every bit as immersive as Diagon Alley. WDW might never admit it, but they've learned a lot about how to do this from the Harry Potter success.