Yeah, the only hit the box office could take is in the future, as scalpers stop buying up blocks of tickets for resale. As it stands now, they're the ones taking the loss while the box office banks healthy grosses, as it has since previews.
My gut instinct is this will be around a while but it probably is not going to be on par with Lion King or Aladdin as a Disney property. It'll run for a bit and then get out on the tour, where I'm betting it will make a massive amount of money.