HEXUS.net posted an interesting article on DirectX10 D3D. Here's a taster:

The GS brings extra flexibility and scope for new on-GPU effects, the spec and API itself cleans up the caps system and more explicitly defines image quality, the runtime has significantly less overhead, the new integer instruction set and HLSL-only should make it easier for developers to write SM4.0 shaders under D3D10, and the OS itself -- Vista -- is the willing and enabling host for it all.

DirectX 10 won't be available on Windows XP, as you might well know by this point, and D3D9 performance will be slightly up on Vista because of the new driver model and runtime architecture. So for a PC gamer, Vista should hold significant appeal in the long term. For the developer, if you also count in tools, docs and general developer support from Microsoft and the main IHVs, it means a system more flexible, powerful and (mostly) easier to use.

That brings us on nicely to what it means for you the end-user (although hello to any devs having a read!), after wading through some of the technical details. The simple reality is that Vista and D3D10 (and to some extent D3D9 while things transition over) will eventually enable developers to create even better looking and playing games and 3D apps, using ever more programmable graphics hardware.

There's a timeframe to consider, since Vista's not even here yet in retail form, but it's coming. The early looks at D3D10 in the first supporting SDKs, on Vista beta and RC builds, hold promise while we wait for hardware acceleration to work with.

Great information