When I looked at the podcast, I looked at Jeff Bradbury's Teacher Cast and Learn Out Loud. Both provide great information and opportunities to learn, but I honestly don't know that I will ever use them. To me Podcast is like professional development, you can't take them too seriously, and you have to find other ways to engage the listener. I typically listen to the podcast on my way to work, and most have some of the humor or engaging content that keeps my interest. If you are going to create one, that can be difficult to achieve.
I think from a classroom perspective podcasting would be very hard, but it would give some opportunity to support those with diverse learning needs. You have to publish them on a regular basis, and you have to make them engaging. I can see those two things causing podcast creation to trail off even though it does give learners more access to content.