No wonder as it lacks the needed registry keys in Win 8.1 . @ OP Only 3rd party tools so far. I don't believe they will bring it as update to Win 8.1, more likely they want us to upgrade to Win 10 .
At least an unsupported 'hack' and not the real deal . It can give you a short peak of the behavior which will appear in later Preview build (or after updates) that's it.