The founder of Voodoo PC, Rahul Sood, says that Microsoft once floated the idea of implementing cross-platform play between the PC and Xbox 360 for a range of titles. Thing is, testing didn't go so well.
The proposal, part of Microsoft's LIVE push, popped up "many many months ago", and would have allowed people playing games available on both PC and 360 - like Gears of War - to take each other on. Kind of like 2007 shooter Shadowrun, only people would actually play it.
Problems quickly arose in testing, however, when Microsoft found that even the best console gamers simply couldn't compete with the accuracy a mouse and keyboard afforded a PC player. "The console players got destroyed every time", Sood says. "So much so that it would be embarrassing to the XBOX team in general had Microsoft launched this initiative."
I know it sounds silly, and in light of Microsoft's recent abandonment (Fable III excepted) of the PC like a thing of the past, but I'd have liked to see this succeed. Sure, it would have had teething problems, but that's what science is for: to test, repair and improve things. I'm sure eventually a nice compromise could have been worked out, if not for competitive play, then at least for the casual user.