I came to the DC CPH code sprint dying to add video and audio support to media. Rob loach pointed me to this library, and it is totally the way to go.
I've made a D7 patch. It:
* Provides a theme_video and theme_audio (very very simple)
* Provides video and audio formatters
* Updates all hooks to use D7
* I moved away from the libraries module model mainly because I don't understand how it applies in D7. Anyway, I implemented hook_library, happy to move this stuff.
* Added a basic README.txt with instructions