Microsoft didn't give us many new details about its Project xCloud game streaming service at E3, but at least we learned one component of the service is going live this October: the ability to stream games from your own Xbox. The functionality will first roll out through the Xbox preview program, and it essentially turns your system into an xCloud server, letting you play your games from a variety of other devices. That's pretty much what Sony has been doing with its PlayStation Remote Play feature, but Microsoft's cloud expertise should allow for significantly better performance.
Update 6/10, 9:30A ET: Microsoft's E3 conference made it sound like the entire xCloud service would be arriving in October, but it turns out it's just the console streaming component. We've updated the post to clarify.