There's no technical reason why Team Fortress 2 couldn't allow PC players and Xbox 360 players to play against each other, says developer Valve.
"We'd love to, technically from our side, there's no reason why we can't," said Valve's Robin Walker, designer and engineer on TF2, speaking to Game Informer.
"It really comes down to knowing Microsoft has announced that Shadowrun is going to do that, but they haven't let anyone outside of Microsoft, I mean we don't have an API or anything."
The first games to support cross-platform play via Microsoft's Games for Windows - Live will be fantasy shooter Shadowrun and a Vista version of Uno. The service is due out on May 18 and will share a subscription with its Xbox 360 counterpart.
Shadowrun however was built from the ground up for this kind of cross-platform play; we're not too keen to find out how it would affect online games in the sequel to our fondly loved Team Fortress.