On Windows 8, certainly. On Windows RT? No.Is there a future for OpenGL in Windows 8?
WinRT the OS discards all of the Win32 API, in favor of WinRT the API (Microsoft's naming is very confusing). And since creating an OpenGL context requires the Win32 API, there is no way to create an OpenGL context on the WinRT OS.
Where OpenGL stands as far as the future of the Windows platform is another matter. If Microsoft ever discards Win32 on the desktop, it's highly unlikely that they'll build a means to create an OpenGL context into WinRT (the API). Without direct OS vendor support, it's very possible that OpenGL simply won't be accessible on Windows.
Of course, the ARB and/or conscientious IHVs could develop a way to back-door OpenGL into the WinRT API. But that's not something that's been publicly disclosed.
To be fair, Microsoft discarding Win32 on Win9 depends largely on the success of WinRT the OS (and WinRT the API). If it is successful as a tablet system, and lots of apps get written for it that cover the bases, Microsoft may well ditch Win32 on Win9. This also requires that WinRT is quickly and widely adopted by developers writing for Windows.
That being said, the principle strength of Windows as an OS is its backwards-compatibility; some applications written 15 years ago for Win95 will still work on Win7 and Win8 without even being recompiled. Not many OS's can make that claim. Breaking this backwards compatibility for WinRT makes sense, because WinRT runs on ARM (so you need to recompile your code anyway). Breaking it for a desktop OS... that's something that would require great care. And in general, I would expect Microsoft to give a long lead-time, letting developers know years in advance that Win32 is being discontinued.
Just look at IE6 and how they still make patches for that.
You assume that this is the reason people use D3D. It's not. The main reason D3D gets used is driver quality; D3D drivers by and large have fewer bugs than GL drivers. This is a consequence of the difficulty of writing a conformant GL implementation, as well as the fact that there are a lot more D3D applications. Thus, D3D gets exercised more often, bugs are quickly found and reported, etc.Why would anyone want to use d3d over gl just for a more robust multi threaded rendering feature?