I like the idea of the Disneyland Resort having its own water park by virtue of the fact that it would add another element to the resort, and like Kelly I too would make a point to check it out just because it's Disney. But as others have said, there is VERY limited space in Anaheim that Disney owns, and I too would prioritize the Third Gate before a water park. After that I'd want another hotel, then a water park would be my third priority. Of course I say all of this with the assumption that Disney could acquire enough land for the water park seeing as their land east of Harbor is marked for the third park. In my own ideal world, Disney would own ALL of the plots of land where all the hotels on Harbor are and Garden Walk, etc. and build up an awesome resort with all these things (3rd gate, new hotels, water park).