Aspirations towards hardware-independent accelerated X.Org graphics drivers were talked about at XDC2012.
Lucas Stach was talking about how to have X.Org acceleration but without having to write any driver/hardware-specific code on the DDX driver side. There's already existing implementations like using the GLAMOR acceleration library or a few Gallium3D implementations.
On the Gallium3D side there's the Xorg state tracker and the XA state tracker for 2D in the Gallium3D world. These three main implementations are accelerating X.Org 2D operations using the 3D drivers for the hardware with graphics shaders to achieve near universal/generic support.
The performance of these three implementations vary as do their state of current development activity, supported 2D operations that are accelerated, and Gallium3D or not. It was during this session where Intel reaffirmed they're not attracted to Gallium3D.