The real problem with graphics on Linux is that no one that matters cares. If Red Hat's, Novell's, Oracle's, HP's, etc. business depended on great open source Linux graphics drivers, then Wayland and associated drivers would have a really good chance. However, it's not a priority. How many man-hours do you think have been spent on the Nvidia or AMD graphics stack? Both of those companies claim that the super-majority of their code is shared between Windows and Linux. I'd say that they've spent $100M on the development.
I just can't believe that G3D/Mesa will get any reasonable amount of development time.
A project like this simply can't be done as a volunteer project. It's too complicated to attract casual developers and insignificant to attract major business investment.