Keith is hoping on or around Monday he will be able to land the work he has been doing on per-CRTC pixmaps. It was this per-CRTC pixmap work that also kept the X.Org Server 1.9 merge window open longer, but it never ended up being merged in that release. Per-CRTC pixmap provides, "multiple scan-out buffers which applications can create and assign to arbitrary collections of CRTCs. These pixmaps can be associated with a window for use with OpenGL or drawn to directly." This would also lead to version RandR 1.4 of this X extension.
Those interested in more technical details about per-CRTC pixmaps can find the details in Keith's proposal, which also describes its benefits as driving multiple monitors where the screen geometry exceeds the capacity of the rendering/scan-out engines. integrating compositing and projective transformation into one operation, eliminating visual artifacts during rotation, and reducing the number of visual operations required to achieve a desired configuration.
Keith's code for this implementation is not yet complete, so let's hope he can get the patches battened away and reviewed by other X.Org developers within the next week before it potentially jeopardizes the February release of xorg-server 1.10. Fortunately, all the ABI driver changes are source compatible. Keith's message calling for the extension of the 1.10 merge window can be found on the X.Org development list.
Shortly after Keith brought this up, Tiago Vignatti shared that his threaded input events is also ready to be merged. He also has other patches ready that would make libpciaccess optional again for the X.Org Server. Unfortunately, Tiago is no longer motivated to land his threaded input or libpciaccess work into the mainline X.Org Server. See here.