While MP3 audio has been used with Divx encoded movies for yonks, the official licensing of the technology from Fraunhofer and Thomson means that the codec can be used in official / legal / commercial content created with the video format, rather than just episodes of 24 downloaded from BitTorrent.More information at The Inquirer
DivX to feature official MP3 sound support

The next DivX video codec will feature official support for MP3 and MP3 surround audio.