OpenGL doesn't run natively on Windows anymore, it's not included with the default out of box windows drivers (for any cards), so that would create support issues for the masses.
You know, I get so sick of seeing this every time a new version of Windows comes out.
Windows has
*never* shipped with OpenGL drivers for a consumer OS. None of them. Not ever. Windows 8 is not approaching the realm of anything new with this. Every time MS releases a new OS people bring up the doom of OpenGL because of this, OpenGL is working its' best to kill itself, no need for MS to get involved.
Well that's just flat-out wrong. Apple is not only one of the major members of the Khronos Group, but they are directly responsible for OpenCL, having created the initial proposal and design specs.
Apple is coming close to RAMBUS in terms of their reputation. I don't think their participation on any standards board is going to comfort anyone right now. They are currently in numerous legal battles over their patents on black rectangles.
I've been keeping up with OpenGL since before it existed(OpenGL is a spin off of IrisGL). In theory it was great, in practice it wasn't. Too much fighting/posturing to make it a truly viable long term solution. DirectX has its' own draw backs with MS playing favorites depending on their mood, but the difference between DX and OpenGL is that DX has someone willing to spend hundreds of millions of dollars to keep it progressing. Proprietary extensions were a god send back in the days of dealing with the anchor around the industry's neck, 3Dfx, but today the advances are all in the finer nuances in code structuring more then very basic rasterization features that one company is hell bent on stopping.