If your lucky enough to have hardware which accelerates OpenGL 1.2 functions, you will definately have tried out its 3d texture parameters. This is definately the way of the future, and all IHV’s should try on making that available to the consumers asap. A lot of industry names are pushing for the whole subdivisional/LOD of models to be integrated into the hardware (some form of GPU), but I feel that is a waste of time. That sort of thing would be great for todays techology, but not for the future. I think the future of graphics lies with volume representation of data, and your ability to manipulate that data in a similiar way todays 3d programs work (Maya/MAX). Basically I’m saying death to triangles (even though they are presently the fastest known way to draw graphics) and bring on the volume rendering.
For the immediate future (1-2 years), I think reflections/shadows are something which I feel OpenGL is fairly lacking in, something which is dying for improvement. The Stencil buffer is presently the “right” way for doing reflections, shadows, and such, which looks ok, however I think that the ARB can add a lot more features to the stencil buffer system than they presently have.
I hope the IHV’s are just realizing the potential with which game developers can use fully acclerated stencil buffer functions to their advantage (most stencil functions on the majority of cards are more of a mini-gl than anything).
Think how many tricks you can use now with the stencil buffer, and how many new tricks would be available applying those and new concepts to 3d textures.