The engine that is driving Dubai is construction. When the construction stops, then so will a lot of the economic activity.
I don't see much evidence of anything taking its place. It's an expensive enviroment to work in with a largely transient expat workforce. This rules out a lot of industries relocating here.
I hear the Lakes water features have already been turned off and the water is a brown colour. Sometihng to do with not being designed properly in the first place.