I think very few people jumped on the bandwagon "because" Disney owns them. I think people "jumped on the bandwagon" because they are making great films with widespread appeal. Part of that comes from the financial stability of being owned by Disney, but that's incidental (could have been, say, Paramount owning them instead and had that result).
In terms of theme park stuff, I think people just want to see stuff actually built at WDW and Marvel -- being popular, owned by Disney, and a big part of their current film division -- seems like an obvious thing that "might" be built if they had the theme park rights for WDW (especially given the IP/cross-branding obsession that Iger has for the parks). But people are just as eager to grasp to the idea of Star Wars or Indiana Jones or Monsters Inc or whatever coming to the parks if given a glimmer of hope.