I don't think you'll ever see it. If they do, it would probably be dumbed down and doubt it would be over 200hp.
EPA regulations, SSCC noise regulations, and the fact that they would have to warrantee it just kill any fun that's to be had.
Someone argued that if they can turbo a Rzr from the factory then they can make a turbo sled...but were talking two different animals. The Rzr is four stroke equipped with a catalytic converter.
I know a Power train engineer in the auto industry and they have concepts that are constantly getting squashed because of regulations. These agencies just don't want us to have fun. Sucks, and I wish we could see it, but I'm just being realistic