For several months there's been developers at Linaro and other organizations (primarily the ARM SoC vendors) working on integrating videobuf2 with DMA-BUF. This work comes down to being able to import and export buffers via DMA-BUF to/from the V4L2 stack, so that buffers could be easily shared with the DRM drivers and other kernel subsystems in an effective manner.
While we're now into the Linux 3.7 kernel merge window, this DMA-BUF/V4L2 work is still maturing. The ninth revision to these patches were published a few days ago and are still actively being discussed on the mailing lists.
This latest revision to the videobuf2 integration with DMA-BUF patches re-base the code on the new Linux 3.6 kernel, add in new support, fix various bugs, and bring in various other minor enhancements. While the work has yet to be merged, at least there's other recent new Video 4 Linux 2 features.