Microsoft pursued a much more aggressive approach, rewriting their API until they got it right. By the time D3D7 came out, the majority of the game developers had already switched. By the time of D3D9, OpenGL was already decomposing. It wasn't until 5 years later (and 2 years behind D3D10) that the new ARB managed to resurrect the spec with v3.0 and it wasn't until 3.2 that developers started taking OpenGL seriously again. 3.3 and 4.0 continue that legacy (only 6 months behind D3D11 this time) and things are starting to look up.
Right now, we have two major players adopting the new specs (Nvidia and Ati), one major player dragging their ass (Apple) and the final player wishing OpenGL didn't exist at all (Intel). Hopefully, Apple will realize the synergy between OpenCL and OpenGL and start supporting the latest specs sooner (it's been two years and they still don't support OpenGL 3.0). On the other hand, Intel is hopeless and only (barely) supports D3D. Their OpenGL drivers are beyond hopeless.
One can only wonder how the 3d landscape would look now, had the ARB followed 3dLab's original suggestions back in 2001. AAA gaming on Linux might not have been such a distant dream then.