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.