What is missing from today's podcasting apps? What is limiting the growth of podcasting through the apps that currently exist.

In my mind, they aren't very social at all. Tweeting moments from shows, opening up discussions from shows, see who has listened to shows, etc. Being able to take a snippit of audio (create a quick start and end point) to share... or even just as simple as using the time code feature, like YouTube has.

If you could build an app from scratch, what would you want in it?

In all honesty up front, I am looking into developing an app to take on these issues. I don't think we've come far enough yet. I am in the preliminary stages right now of research... so I have a long road ahead, but am curious to what others think about what is missing from today's app offerings.