I think podcasts for anything teachings is way cool..imagine having Music Delighting The Ocean of Protectors by Trijang Rinpoche or the story of how Dorje Shugden came about on podcast. People these days are travelling more than infront of their computers to spend reading the book..so imagine having these teachings on the go. They can listen to it anytime anyday.
I guess in this day and age, all avenues to spread any form of Dharma teachings should be used and considered as it appears to different crowds ... and by doing this, you expand to more people!
I know people who listen to audio books.. I've got a friend who listens to audio books whilst he is driving, whilst he is cooking, whilst he's chilling at work. I asked him why, isn't it boring to listen to someone read you a book? He said no, because he can do other things as well as listen, instead of just picking up a book and reading, limiting himself (but of course he still does like to read once in a while at the park). It's just awesome that there's this avenue that he can flip between. So yes! podcasts f'sure!