MS has been promising that since the original Xbox.
It isn't going to happen. It would mean days at best until a homebrew if they do, not to mention intra-brand competition between X1/PC games, and said PC games would stutter horribly as they try to page graphics data into the slow-ass DDR3 DRAM.
Sony has slighlt better hardware to pull it, but they aren't going to do it either.