While I have been impressed by the significance of podcasting as process (individualized media, etc.), I can’t say I have been able to offer examples of significant podcasts. Good podcasts I might be able to identify, but nothing that might be an example of what I would regard as significant work.
I think I now have come across my first example. If you are a fan of rock music or experienced the ’70s at a time when your life and values were being shaped, I encourage you to download the iTunes podcasts recognizing the 30th anniversary of Bruce Springsteen’s “Born to Run.” There is something about this series of podcasts that offers the audio equivalent of a great documentary. Check it out and see if you agree.