Though I'm pretty knowledgable in economics and the other social sciences, I've never taken an official accounting or finance course and have spent my entire working life in education; so feel free rip my take on this issue:
I see this huge capex expenditure as a realization/confirmation that some in the upper levels of Disney management realize that they've leveraged WDW as much as they can through cost cutting, price increases, and attempts to manipulate consumer behavior. In order to get a better ROI, they've decided to actually allocate significant resources to increase revenue at WDW, and DHS in particular, through building new attractions. If this budget has truly been approved, it shows that Disney believes the new projects will bring a significant ROI, and it must be pretty significant if Bob I hate spending $ on WDW Iger felt comfortable bringing it to the Board. Therefore, even if Shanghai does flounder in its opening years, I don't see Disney pulling money away from the projects at WDW, as each dollar pulled from WDW would need to go somewhere with a higher ROI in order to make financial sense for the company. And it typically is not wise to throw good money after bad.
To make matters worse, WDW has stagnated so long, especially DHS, that a half baked Star Wars land or Pixar land could have a very negative impact on Disney's public image and by extension, bottom line. There are already enough people who are upset that the DHS they once loved is a shell of its former self. Hopefully, a well executed Pixar and Star Wars land will win those guests back, or at least be offset by a larger increase in Star Wars/Pixar fanatics. However, each hypothetical dollar that Disney pulls from the redo, would be one dollar closer to Disney Jar-Jar'ing themselves and creating a hollow and soulless Pixar/Star Wars experience. This would not only lead to poor PR, but would result in being despised by former Hollywood Studios fans and rabid Star Wars fans alike.
Finally, if Shanghai does struggle, I think that Disney would want to hide its struggles as much as possible to prevent embarrassment and actual difficult questioning from shareholders (which is one thing it seems very capable of...) Slashing the budget of what I'm sure will be a highly anticipated and publicized Star Wars/Pixar expansion, would reek too much of desperation, weakness,and admittance of failure.
For these reasons, I think the budget will be pretty safe. The real test will be how efficiently the massive budget will be put to use.
Again, I'm no business wiz kid (not everyone can be a Tom Staggs), but those are my thoughts.
