Re: Counter strike on xbox
An official announcement is supposed to be made mid-May (at the E3 Expo) regarding the Xbox version of Condition Zero.
The Xbox version is rumored to be slated for release around Christmas time. A co-op multiplayer mode hasn't been ruled out completely yet. Castle, a level designer on the CZ team, did state previously that he had run into a "few very difficult issues with co-op mode." Keep in mind that Valve hasn't revealed who's the developer.