I'm going to simply interpret that as the gaming front end of Microsoft's planned "App Store" to rival Apple's. They want a singular game service (which is probably also why GFWL is relocating to Xbox.com) and want media bought from that service to be shared across devices. Maybe it works in a way that buying a game that has a PC and Xbox version unlocks that game for both devices. Same applies for Windows Phone (Which is also branded with Xbox Live). I'm not sure about the specifics, but it might also explain why Microsoft was adamant about not putting Steamworks onto Xbox Live. If they had planned all along to do the same thing as Valve, except on their own service, they wouldn't like competition on their own platform.
In the end, it comes across as the bitter truth that Microsoft is attempting to take control of the PC gaming market. They have this blind mentality that because people play on their OS, they have a right to control the games on it. Steam has been a thorn in Microsoft's side for too long, and Microsoft wants to reclaim its "birthright" of superiority.
I love the Xbox to death, but I'm enamored with Steam. I'd like to retain my ability to choose my service, and not have a Microsoft product forced on me if I upgrade to Windows 8. Which, with all that I've seen, I just might not do, but I hate to be forced into that choice.
Does anyone know if this would pass in the EU? They almost didn't let Windows 7 release as-is because it included Internet Explorer as a browser by default. They wanted to have a browser ballot screen on install where you could choose your preference before you actually use it. Could we end up with a digital distribution ballot for games too?
Huh...
Is this the start of, "All games played on Windows must be played on Xbox Live."?
Or is it just a simple, "Hey while you're on your computer talk to your Live friends!" and stuff like that? As well as an integration of other Xbox Live features.
You can already do that with Windows Live Messenger integration with Xbox Live. It's not implemented in the best way though.
My guess, like I said above, is just a marketplace where you can buy games, and if it's a game that is available for PC and Xbox, you could get it for both with one purchase or something.