David Airlie has sent out a notice that soon he'll try to go forth with a pull request that will cause more API/ABI breakage for the X.Org Server.
Airlie basically sent the mailing list message
as a notice and not an official pull request yet. David will call upon Keith Packard to pull the changes once he's made the main X.Org drivers (Intel, Radeon, Nouveau, etc) compatible with the new API. So the open-source drivers will work immediately with the new X.Org Server API changes, but will leave the NVIDIA and AMD Catalyst binary drivers broken until the corporations issue their new driver updates.
This work comes on top of other recent driver API changes
for this wasteland of unreviewedness