While post formats seem to have fallen somewhat out of favour, I still like the idea of managing various media types as I develop content as the featured type, but as a developer I also have to write an inordinate amount of code to grab a video / audio URL out of the content, working it into the index is a mission and generally its been an unpleasant experience all around.
I'd love to have a discussion around turning the simple featured image implementation into a 'featured media'.
I this as a natural evolution of both the media library and a great way of working with this kind of functionality, bring an incredibly easy to use workflow to users, and a great way to standardize working with featured media for developers.
I think this is a very simple, but a very 'meta' idea that could solve many issues, on many fronts.
PS: If i've tagged this wrong let me know - not sure if it should be in media / editing / UI etc.