Valve should start supporting OpenGL. There's nothing it can't do that DirectX 10 does. Plus it's a friggin open standard. Porting opengl games to linux and macos is not difficult. It's nice that valve is bringing these issues up because it's pathetic what ms is doing. It's just that actions speak louder than words.
For those that are supporting MS' vista initiative, what are you guys thinking? This OS oozes of rights management and proprietary standards. Now you're feeling the result of adopting crappy proprietary standards- it's creating unnesessary driver incompatibilities and is dictating the direction of PC gaming to suit MS' needs. MS wants to control all of your media, including games. We need to support gaming on other platforms.