@manton Was amused (I may or not have talked to my phone) that when exploring different ideas of what could go on the 'shelf', podcasts didn't come up!
But seriously, to add to the guiding principle part of the convo, I think if the question is 'does it support and help MB users share what they would on their blog', then books+media fit that description in the same way that photos or video hosting fits that description.
I can't see why MB couldn't integrate with an API like the Podcast Index or Listen Notes which would allow me to share to the blog+feed an episode I found interesting. In fact, I'm biased towards the former (although I love what LN has been doing) as they've enabled a soundbite tag in the namespace for podcasters to mark snippets for sharing.
Like books, it would enable sharing episodes like I did here, but without the steps I needed to clip out and then embed them.