I think it's better for now to focus on Ati & Voodoo because we all use an Ati or Voodoo card. Dazzle us with good (3D) drivers for those cards and once that's working perfect go work on drivers for other brands.
I don't want to get in a hypothetical situation that we have great drivers for Nvidia and that there's possibillity that the drivers for Ati still don't support 3D. Which could mean that we are forced to buy another card if we want to use 3D in MorphOS.