^I have no idea, but from the tone of your reply, it sounds like you haven't been to the one in Florida, or if you have, you were pretty unimpressed. But I've been, and even as a not big Harry Potter fan, I was totally amazed by the area, and found it to be one of the single most themed areas I have ever experienced in a theme park, period. Iconic or not, it was amazing. Isn't that enough? Really, tons of people are now visiting Universal largely on the basis of Harry Potter... so why wouldn't they dedicate a large amount of space to it? I still think there's plenty of other stuff to do that's not Harry Potter related.
Plus, many here have already mentioned that Hogwarts Express wouldn't fit, and I personally feel that's true as well.
Now, the space issue.. that's the big one that's still up for grabs, if you ask me.