Cisco has taken their H.264 implementation, and open sourced it under BSD license terms. Development and maintenance will be overseen by a board from industry and the open source community. Furthermore, we have provided a binary form suitable for inclusion in applications across a number of different operating systems, and make this binary module available for download from the Internet. We will not pass on our MPEG-LA licensing costs for this module, and based on the current licensing environment, this will effectively make H.264 free for use on supported platforms.

More information at Cisco blog post at:
http://blogs.cisco.com/collaboration/open-source-h-264-removes-barriers-webrtc .

And the Mozilla blog post at: