The Microsoft DirectX slides are available for download here.
This download includes presentations given by the Windows gaming and graphics team at the Game Developers Conference 2005. Included is the Microsoft DirectX Developer Day content and the High-Level Shader Language (HLSL) Workshop content.
The nVidia slides are available for download here.
http://developer.nvidia.com/object/gdc_2005_presentations.html
The ATI slides are available for download here.
http://www.ati.com/developer/techpapers.html#gdc05
Enjoy.