The move away from Flash is ever so slow, but at least there is movement. Starting with Firefox 20 (due out in April 2013) Windows users will have support for H.264 videos via the Windows Media Foundation Playback. Also Firefox for Windows will be able to support AAC audio in MP4 and M4A files, and MP3 audio files without having to rely on third-party plug-ins such as Flash and QuickTime. This feature is available, but not enabled on the current Windows Firefox Nightly Builds. Those currently using (can also get it here) the current Firefox 20 wishing to take advantage of this…