https://www.youtube.com/watch?v=IzV_xrisMko

"The future of gaming is a world where you are empowered to play the games you want, with the people you want, whenever you want, wherever you are, and on any device of your choosing. Our vision for the evolution of gaming is similar to music and movies — entertainment should be available on demand and accessible from any screen. Today, I’m excited to share with you one of our key projects that will take us on an accelerated journey to that future world: Project xCloud."

About Project xCloud

Scaling and building out Project xCloud is a multi-year journey for us. We’ll begin public trials in 2019 so we can learn and scale with different volumes and locations. Our focus is on delivering an amazing added experience to existing Xbox players and on empowering developers to scale to hundreds of millions of new players across devices. Our goal with Project xCloud is to deliver a quality experience for all gamers on all devices that’s consistent with the speed and high-fidelity gamers experience and expect on their PCs and consoles.

Full Article:  Official blog

We knew they had this in the pipework since they announced it on stage at E3 earlier this year but this was sooner than I expected them to be announcing it, Could be with Google getting their plans out in the open Microsoft also wanted people taking note of their future streaming service.