And the great thing about this project is that if a graphic hardware vendor needs to choose what to spend 1000hours to work on, it can now be the 3D driver instead of a 2D driver. Because someone else created a layer to use that 3D driver for all 2D operations.
Previously the money/time was spent on the 2D to facilitate the largest target audience for the hardware and unfortunately that 2D effort could not be utilize for the linux 3D use case, so no wonder improvement to it were hard to get.
So expect those crappy 3D drivers to get good in the areas needed by the 2d-over-3d code real soon and while they are in there they might as well work on all the low hanging fruit concerning 3d usage.
So won't apply your previously knowledge on linux 3d driver support against what the future will now bring to both the 2d and 3d scene.