We are about to merge in support for audio derivatives to Timed Media Handler (TMH). The big value here, I think is encoding to AAC or MP3 and adding a listen to this article feature to the mobile app.
https://gerrit.wikimedia.org/r/#/c/39363/

This can really help with improving accessibility of Wiktionary pronunciation media files as well.

Also AAC / m4v ingestion, could make audio recordings a lot easier to import into the site, i.e a "record a reading of this article" mobile app feature #2  ;)

There are already thousands of spoken articles, with some promotion their could probably be a lot be more:
http://en.wikipedia.org/wiki/Category:Spoken_articles

The software patent situation for mp3 is sad, considering how long the mp3 format has been around:
http://www.tunequest.org/a-big-list-of-mp3-patents/20070226/

I think AAC is a similar situation, encoder wise:
http://en.wikipedia.org/wiki/Advanced_Audio_Coding#Licensing_and_patents

But fundamentally Wikimedia is not "distributing" these encoders and there are no royalties for media distribution. Likewise we are not shipping decoders ( the decoders are in browser or the mobile OS )

I don't know why Wikimedia's commitment to being accessible in royalty free formats, somehow also precludes making content accessible for folks on platforms that ~don't~ decode royalty free formats. But hopefully we can change that over time.

Not sure if this is the right forum for this, but I hope we could come out of this thread with rough consensus to enable these formats to help increase the reach of audio works.

peace,
--michael