I've used podcasts before. They can be nice - I've had then set up in iTunes to go to my iPod. Unfortunately - I don't have a morning/evening commute, which is the 'desperate to listen to something' period for me, so I never end up listening to them.
I've added the link for one to Feedburner, which strikes me as hilarious - Podcasting without the Pod. Re-adding the tether, having to sit at your computer to listen to something that by design was meant to be something that you could take with you... like a radio station that would automatically appear in your mobile music device overnight.
If I'm going to have to sit at my computer - unless the contents of the audio are musical, dramatic, or otherwise enhanced by remaining audio - I don't want to hear about it, I want to read about it.
I can read faster than I can be talked at. I can fast forward, jump back at will. Rereading is an option, as is skipping entire sections. When dealing with an audio file, you are locked into a presentation. You have to be an amazing speaker in order to hold my attention in a podcast, unless I'm a captive audience already (driving, for instance).