Polycount has the source art for the models for version 1.0 of Counter-Strike. Word accompanying the files is that they are "still 'copyright Valve 2000-2001 (all rights reserved)' and to add that it is free for non-commercial use only - ie you and/or the mod makers can't charge for redistributing it." Also, there is an interview with Scott Bilas on The Siege Works discussing what will be involved in creating modifications for Dungeon Siege, Gas powered Games' upcoming RPG.