Today, Microsoft sent out invites to let a small set of users play Xbox content on your iPhone and in your browser. While my video on using Cloud Gaming (xCloud) on your iPhone will land on Thursday, today, you can see what it is like to use the service in the browser.
The short version of the video below is that first-person games like Minecraft Dungeons are an experience I would recommend to others. But on the other side of the coin, games like Gears of War, especially the multiplayer aspect, needs improvement before I would recommend users jump into that arena.
That being said, this is still an early iteration of playing Xbox content in your browser and the initial experience is quite good, as long as you understand the basic limitations of the speed of light.
For now, check out the video below as it has a bit more commentary but also in-game clips to show how Microsoft is bringing Xbox content to the browser.