The Big Nouveau Rework Will Indeed Land For Linux 4.3
Ben Skeggs of Red Hat who maintains the Nouveau DRM driver explained the work in the commit, "Beyond correcting some not-so-great design decisions and making the code a lot easier to work with, there's not much exciting (lower memory usage, GPU VM should be a lot faster, etc) to be gained by the end-user as a result of the cleanup, it mostly lays the groundwork for future improvements."
There's also Tegra X1 (GM20B) graphics support, perfmon work, support for GT200 re-clocking and other power management improvements, Maxwell DisplayPort fixes, random fixes, and support for NVIDIA external firmware as mentioned in my article earlier in the week. However, I have yet to see NVIDIA publish this signed Maxwell firmware/microcode anywhere yet.
After Linux 4.2 didn't bring any Nouveau changes, I'm looking forward to testing this big driver rework in Linux 4.3.