It doesn't sound as though it will be very big. I would have liked it to be as tall as the Haunted House. With any luck this one will sell really well and we might see a bigger one, akin to the modulars, in the future.
Even if this one is on the small side, I'm pretty sure I'll be buying it. My wife and I have been talking about how cool a Disney Castle in LEGO would be for a while. My dark age was when the Harry Potter sets came out, and she would have loved a Hogwarts Castle. This will be a nice substitute, regardless of the size.