Also OpenGL is now overseen by the Khronos Group (rather than the ARB, which was run by SGI - when SGI went under, my understanding is that things became considerably more complex for the ARB). One reason that OpenGL lost was due to the fact that while Microsoft standardized the programmable shading language early on with HLSL, OpenGL has had three or so different languages, support for which varied across different graphics cards. This means that it is complicated for developers to support the same feature across different graphics card vendors. With OpenGL and the ARB, graphics card vendors would come up with their own features all implemented differently in the hopes that their extension would get promoted to "EXT" (official extension) status, and then to "ARB" (architecture review board core extension status). One of the advantages of DirectX is that Microsoft tries to dictate what features graphics cards must support - this pushes the technology in a certain direction.
Sometimes the extension will be reported as supported, even though the the OpenGL implementation decides to fall back to a software rendering path (extremely slow - unplayable).
With OpenGL you are forced to query drivers for various OpenGL "extensions," where an extension is basically a supported feature. I think probably the main reason that DirectX has won out in the marketplace over OpenGL is the fact that you can say something like, "This game requires DirectX 9.0" or "This game requires DirectX 8.0," and if the user's hardware is compatible with that level of DirectX then the game has a high probability of running.
I doubt each console allows the same openGl commands to run and they probly all have custom extension and little gotcha that are platform unique when it comes to OpenGL I don't know for sure, but i can imgaine that even with openGL, you would still have to port the display part of the game to whatever console.
How many times do you see that ever happen? It's rare to see a pc game move to a console, and even rarer for it to be made by the same people. I am surprised by the dominance of DirectX in the current climate of spiralling development costs and Developers' needs to extract every last dollar from a given title.ÄirectX is a solid product, but would seem to be a poor choice going forward.
OpenGL would seem to be a no-brainer for titles that will have cross-platform appeal. A million unit seller is a blockbuster PC title, but merely a decent seller on a mature console. Windows has the lion's share of the PC market, but that market pales in comparison to the console market.
So, it means that you can get the best result out of your laregest market while still making your stuff available on other platforms. That said, while direct3d may sometimes have speed performance benefits, image quality performance benefits, and high integration (.net) if you're programming for apple Mac, or the playstation, or the nintendo64, or the ps2, or the gamecube, or the wii, or the ps3, why waste time on direct3d? Because, as you said earlier, Windows has the lions share of the market.