For those that were hoping there would be NVIDIA GeForce 400/500/600/700 Fermi/Kepler GPU improvements or better re-clocking or anything fundamentally advanced in the Linux 3.12 kernel for the Nouveau graphics driver, that is not the case.
The Nouveau DRM driver changes for the Linux 3.12 kernel are sadly disappointing. There really isn't much feature work for this next kernel cycle with regards to the open-source reverse-engineered NVIDIA driver. The only exciting feature bit there is to talk about are the kernel changes for allowing the VP3 video engine
to support MPEG-2/VC-1 video acceleration
in conjunction with Gallium3D updates.
The merge with the bug-fixes for Nouveau can be found in drm-next
. At least there's a lot of other exciting features
for Linux 3.12 including but not limited to Intel driver improvements
and DRM render nodes