Early changes with this open-source NVIDIA driver for Linux 4.12 includes re-architecting some of the code to better handle NVIDIA's proprietary firmware images and related changes. It also introduces the firmware changes for supporting the NVIDIA firmware of the GeForce GTX 1050/1060/1070/1080 series "Pascal" graphics cards.
A few days ago was when NVIDIA published the accelerated Pascal support for these newer consumer graphics cards. With that they also released the needed signed firmware images for allowing the accelerated support. While the Pascal accelerated support is now here, there isn't yet any re-clocking support or other advanced features -- it's basically in the same boat as Maxwell, while the best Nouveau support currently remains with Kepler hardware.
More details on these early Nouveau changes for DRM-Next / Linux 4.12 via this Git pull.