What if they go to MK because it is "Disney World" but skip the other 3 parks?
Personally I think MK will still be #1 but the other 3, especially AK and DHS, will be hurt by Potter. I mean AK is only getting "extended hours" as a part of the Nightastic! promotion (and that promotion likely is what's begin done to combat Potter, it can't be any coincidence that the first time in many years Orlando does a seasonal promotion without a hard ticket party is the same one Potter opens).
As for Fantasyland and Star Tours they apparently never were meant to combat Potter according to Martin. The 4 that were:
Space Mountain reno (which did happen to a smaller degree)
Have obviously not been done in time to do so (if they all get built one day).