IIRC, they ditched the idea of console vs PC cross-platform multiplayer in the past for precisely that reason:-This has the potential to allow PC gamers into the Xbox world. Stream the new CoD to your PC and use a mouse & keyboard. It'd be a slaughter.
"I've heard from reliable sources that during the development they brought together the best console gamers to play mediocre PC gamers at the same game... and guess what happened? They pitted console gamers with their 'console' controller, against PC gamers with their keyboard and mouse. "The console players got destroyed every time. So much so that it would be embarrassing to the Xbox team in general had Microsoft launched this initiative."
http://www.eurogamer.net/articles/ms-killed-pc-xbox-cross-platform-play
http://www.techspot.com/news/39738-...because-pc-gamers-wrecked-console-gamers.html