This is a big problem for Haiku. No hardware 3D. But one that needn't be insurmountable. The answer to this problem lies in completely circumventing the problem itself. In other words... stop trying to write drivers to access hardware accelerated 3D in the video cards we have in our systems that the video card companies aren't going to ever give us the specs to...
I'm sure you're scratching your head, going, "What the... huh? How can that possibly solve our problem?"
The answer is simple... if you can't figure out how to write hardware accelerated 3D drivers for video cards that other's make... MAKE YOUR OWN VIDEO CARD!
Now, what I propose may seem insane, but it really isn't. It's simply creating a work-around solution that will, in all likelihood, provide what we want (playable 3D gaming), in a way that let's us define exactly what the card can do and how fast it can do it.
Now, before you start telling me that designing a video card takes millions of dollars and fabs to create the chips and all that stuff, let me tell you that the hardware portion of the answer is likely right where you're reading this and the initial code to make it function is only a download away.
If I have your interest piqued, do reply and/or Email me. You're not gonna believe the answer... it's a very primitive solution, conceptually, but (in theory) it should work faster than the current software solution we're having to use presently.
I just need someone (or a couple people) willing and able to give it a try...