I'm totally new to the Mac environment and became curious when you said osx doesn't support direct3d. Why don't they? And why do the Mac graphic drivers get updated less frequently? Is it a matter of pc Mac market share and nvidia goes where the market is?
The reason they dont is that Direct3D is a Microsoft technology, so as you can imagine from the beginning of time, there has been and probably never will be support for D3D (or directX) on mac.
Which means mac runs everything using OpenGL.
Now the market when it comes to applications, games etc are all first developed for D3D because of a lot of reasons. the market is endlessly much bigger, easier to code, opengGL gets developed slower (I think) general concern and support for opengl is a lot less overall. An example is Autodesk just released their 2014 series, 3ds max, maya, mudbox etc and most of them now support DX11 in their respective viewports.. but hey! DX11 is a directX technology, which means all that is not supported on mac, maya 2014 for example.
When it comes to new nvidia drivers for mac its all because of APPLE. In theory nvidia could develop and release drivers side by side with the PC, but like everything else apple, it has to go through apple and be authorized etc, think iphone app store, you can't just make an app and upload it. Its a long and slow process.
So you never see any custom or modded nvidia drivers for mac. which is a massive shame because you 100% rely on apple not being in slow turtle mode which they have been the last 20 years.
That's about it
🙂 Luckily if its a concern at least you can run bootcamp and thereby windows 7/8 on your macbook pro etc and then of course, because you are in windows you have access to it all.
So final words, OS X will probably never support DirectX.