That would be assuming that the best technology always wins these battles. I agree that in video OpenGL 2 versus DX9 is superior.
However as mentioned above the nice thing about DX is that it handles much more through it structure making it easier in some ways to develop video, sound, and input.
In my experience DX is easier and more robust when developing games, not necessarily better as far as video.
Personally I have hope for OpenGL as I would love to not ever have to boot up windows anything again.