A friend showed me this article that states that Microsoft was going to try and cross platform when it came to multiplayer and such (like Gears of War) on Xbox 360 and PC but after testing they found that

"'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.'"

This makes me laugh, maybe developers will create the respect us PC gamers deserve

http://www.kotaku.com.au/2010/07/rumour-microsoft-killed-plans-for-pc-vs-xbox-360-online-play/