This IS necessary (Score 5, Informative)

There seem to be a lot of posts stating that the current OpenGL implementation is good enough but I question whether or not these people are developing software with the latest graphics features.

Vendor specific extensions are making cross-vendor OpenGL development difficult. It is necessary to implement several different codepaths in order to achieve various effects on different hardware (bump mapping, cubic environment mapping, etc.) because each vendor wants to do it their own way to expose all of the new capabilities of their hardware. The SGI multitexture extension is probabily the only real exception to this since it seems to be supported by the bulk of cards on the market.

I don't know of any current AAA, A or B grade game that doesn't support at least one proprietary OpenGL extension.

DirectX8 exposes the hardware in an 'almost' abstract manner but again vendor specific features have started to creep into the mix (the different shader version support is something that comes to mind), meaning that developers still have to develop multiple versions of the same effect for different hardware.

This is definately a great move! I hope they succeed!