According to the site here it's only a matter of time until Gears of War ends up on the PC.  We already have a ton of game ports, but what  I would really like to see a convergence of titles where PC gamers can interact with console gamers, and it has happened with Final Fantasy (PC and PS2).  Here to hoping with the new consoles out that we see more games include multiplayer across multiple platforms (other than just PC and Mac).