A commit this morning to Mesa by Maarten Lankhorst read, "nvc0: add support for accelerated video decoding through the dedicated engines Currently the use of external firmware is required, with kernel and userspace firmware needed for all Fermi cards except nvd9. Kepler and nvd9 should only require kernel firmware."
The NVD9 is the GeForce GT 520 graphics card and Kepler is the newer GeForce 600 series. Exposing video decode acceleration for this newer NVIDIA GeForce hardware in Nouveau was around two-thousand lines of new code in Mesa this morning. This video decode support builds upon earlier Nouveau work too, including yesterday's Gallium3D NVC0 driver work on exposing the video buffer, etc.