There was a series of articles on I-Drive in the Orlando Sentinel a few weeks back that also touched on this.
As I recall, Universal rents the land Wet n Wild sits on, per the originial contract from the 70s, the rent is already going up, and within a few years the contract will expire or at least the lease rate will be uncapped. The orignial builder of Wet n Wild was quoted as saying he fully expects Universal to move all the slides etc. somewhere onto Universal property in "20xx" (I seem to recall it as 2010, but it may have been 2007). And, yes, he seemed to be serious.
My own two cents: Not sure why Universal is spending tons of money on their new Disco H20 ride (including a fortune on advertising) if it will be gone in two years. And wouldn't it be cheaper to just keep the name and build a new park from scratch? That said, the landowner probably believes he can make more from a year-round luxury hotel than he'll be able to get out of Universal. Stay tuned...