I guess it would depend on how much market they feel they can capture. See how the third gate goes and see if the demands there for 4
The big question is where would they they get the staff to run the two parks? Supposedly the labor market in Orlando is just about maxed out.
Both good points, but I guess I didn't define what I was thinking very well. The idea of building 2 parks instead of one larger park has only one reason - if they think that it would be a benefit in the eyes of the consumer. Because otherwise, building 2 parks is going to create both greater operational expense as well as greater capital expense in construction.
Each time you add a park to your complex - the benefit diminishes.
Building 2 parks over 1 park has a benefit - the benefit is you become a multi-day destination vs a single day destination (like Sea World or Busch Gardens)
Building 3 parks over 2 parks has a benefit - you become a week-long destination, and can truly steal from the competition (Disney)
Building 4 parks over 3 parks has little benefit - people in general don't stay beyond 7 days. Disney learned this with Animal Kingdom. They built it, and when it opened, overall attendance was essentially flat, they simply took attendance away from themselves.
So - while I can see 3 parks benefiting their business - 4 parks just won't help much - and the result could be worse too. If you build a single big theme park, it will be perceived as a huge success. If you build two smaller parks - well, people will complain that they don't consume a full day.
The exception would be if they considered building some sort of boutique park,a la Discovery Cove, with high cost and limited capacity. I think that highly unlikely as well, it's extremely risky to place a small fortune on a single concept.