An appeal to the planners' decision was planned, but now developers have announced that they have abandoned the project. Instead they will try to get the parcel of land rezoned as commercial, with the specific clause included that no amusement park will be built.
If Orlando Thrill Park had been built it was to include large roller coasters and rides from major manufacturers around the world. Notably, a Top Thrill Dragster/Kingda Ka clone was consistently shown in artwork of the park. Another one for the history books, I guess!