The H.265/HEVC codec was approved at the beginning of the year and doubles the coding efficiency of H.264 and also brings other improvements while being competition to Google's free VP9 codec that's an upgraded VP8. While early on, there's also the Xiph.Org Daala video codec getting into the mix as well.
For open-source H.265 support we have seen the x265 project started and then libde265 as another HEVC decoder project. Last month, the VLC Media Project implemented H.265 support via the x265 code.
FFmpeg developers are now using OpenHEVC as their native H.265 decoder implementation. The latest Git code to FFmpeg now supports H.265 while HEVC demuxing support was also added to the TS, MOV, and Matroska demuxers.
More details on this major addition to FFmpeg can be found via the Launchpad announcement.