I think it will bite them in the ass the same way glide did for 3dfx. Vulcan/SpirV may end up as the openGL of heterogeneous computing. Nvidia has the momentum at the moment with a focus on GPGPU, but if we can get an open API that leads in performance across vendors for both CPU and GPU we'll see that competition again. We just have to hope that nvidia doesn't nerf their implementation like they did with openCL.
NVidia was clever to see that no one wants to code GPGPU code in C, rather leverage their C++ source code and the Fortran libraries with decades of investment.
So CUDA has been language agnostic from the first day.
Khronos has realized their error by creating SPIR, but it might be too late already.
Also the debugging experience for CUDA has always been quite good.
Not a shame for game developers. It's nice to have some ability to predict that the failure modes where cards diverge from specification will tend to diverge along the same paths, because they're made by the same vendor.
Granted, it'd be preferable to live in a world where the drivers and hardware are open and inspectable (so you don't have to debug graphics issues as a black-box problem), but we've never lived in that world and between the likelihood of AMD's initiative taking root and a de-facto Nvidia monopoly, I'd rather have the monopoly.
