SamuelRSmith on 09 December 2008
It's technically not out of the realms of possiblity in terms of actually being able to do it, it would basically just be getting permission from Microsoft/Sony/Valve to do it.
I would assume that Microsoft would have the biggest issue with it, because you have to pay for XBL, whereas the others are free (may make people question the subscriptions), they're also directly competing against Steam on the PC market, and XBL/GFWL cross-playing is one of their selling points.
