A couple of months ago, Project xCloud streaming was embedded into Xbox Game Pass Ultimate to allow Android users to stream all sorts of Xbox titles from the cloud to their mobile devices (this functionality is not currently available on iOS due to limitations imposed by Apple).
Microsoft's Head of Gaming Phil Spencer confirmed that while mobile has been the primary focus of the xCloud streaming initiative, PC and even Xbox consoles will be eventually supported.
Now, WindowsCentral managed to get hands-on with a PC version of the testing app. Everything seems to be working in a very similar way to what we've seen already on the Android platform, though there's a caveat - the resolution is currently stuck to 720p, as the servers that currently power xCloud streaming are based on Xbox One S hardware. While this isn't a big issue on small screens like smartphones and tablets, PCs are generally connected to far larger displays where 720p isn't really a desirable resolution anymore.
This problem will likely go away next year when Microsoft is planning to replace the Xbox One S-based server blades with the much more powerful Xbox Series X hardware. The resolution of xCloud streaming should go up to at least 1080p, if not further than that; after all, Google Stadia has offered 4K streaming for a year now, and the upcoming Amazon Luna should support 4K resolution 'soon'.