I hope WDI takes up the "challenge" of creating original characters, music, and stories more often. They aren't going to discover the next generation of Pirates of the Caribbean and Haunted Mansion caliber attractions being forever tied to existing IP (although I'm sure there will be no shortage of such IP-dependent attractions in the years to come). Mystic Manor, along with Sindbad's Storybook Voyage, has helped to reinvigorated my hope that new classics can still be created at the Disney parks.
I'd also love to win the lottery, but that's probably not going to happen, either. :^(
I'm sure they realize they struck gold with this attraction. Great story, great effects, great music, and great family fun as only Disney can provide.
Mystic Manor appears to be an amazing attraction. It would instantly crush the new Harry Potter attractions at Universal and the penguin attraction at SeaWorld, but maybe we have to settle for Star Wars, Carsland, and Avatar in the next few years.