This is a step forward in finally reaching a standard video format on the web. Despite over 80% of online video being in H.264 format, Mozilla has previously refused to update it web browser with support for the standard.
If no major issues are found, H.264/AAC/MP3 support should ship in Firefox 22, which is scheduled to be released around June 25th.
For Linux and Mac, work is in progress.
Read More [via Engadget]