You may have caught this headline last week:
The MP3 Is Officially Dead According To Its Creators
It is worth a read, but make sure you read Marco Arment’s followup:
“MP3 is dead” missed the real, much better story
In summary:
MP3 is supported by everything, everywhere, and is now patent-free. There has never been another audio format as widely supported as MP3, it’s good enough for almost anything, and now, over twenty years since it took the world by storm, it’s finally free.