Castrum - CS: GO will feature cross-platform online play (as in, PC gamers can play against PS3 gamers) at launch. To counteract the advantage PC gamers would have over console gamers, PS3 players can use a Keyboard/Mouse setup instead of the DualShock 3 controller.
However, the 360 is being left out of this equation, partly because of Microsoft's asinine restrictions on Xbox Live, and partly because Gabe Newell is a Sony sell-out.
Source: Joystiq
Ok so MAYBE it will have one redeeming feature, the chance to show the console*beeeeps*s the might of the glorious PC gaming master race.