Firefox 21
Currently available in Beta, Firefox 21 is targeted for May 14, 2013 release. WebRTC will finally be enabled by default.
WebRTC offers web application developers the ability to write rich, realtime multimedia applications (think video chat) on the web, without requiring plugins, downloads or installs. It's purpose is to help build a strong RTC platform that works across multiple web browsers, across multiple platforms.
Firefox 22
Available in Aurora channel, you can expect to see the final build of Firefox 22 on June 25, 2013, which will block third party cookies by default.
Firefox 23
Currently available in the Nightly channel, Mozilla will push the final build on August 6, 2013.
Version 24
Lastly, Firefox 24, which is scheduled for September 17, 2013 release.
And now we wait.