DMA-BUF V4L2 support has been a work in progress for several months, but with Linux 3.8 the support has finally landed. This support allows for zero-copy buffer sharing using DMA-BUF so that, for example, a DMA-BUF-supported V4L2 driver could pass a buffer to be imported by a DRM graphics driver without actually needing to copy the buffer. Supported V4L2 drivers (such as the s5p-fimc V4L driver) can import and export buffers using DMA-BUF with other Linux kernel drivers.
The Video 4 Linux 2 DMA-BUF buffer sharing support is part of the media updates pull for the Linux 3.8 kernel. Aside from the DMA-BUF support, other media changes for Linux 3.8 include a "s3c-camif" Exynos hardware driver, various warning fixes, and then various bug-fixes, clean-ups, and driver improvements.