Elizabeth Crane in the April newsletter from the ASJA discusses the writer's point of view of podcasting:

Anyone can record a podcast and become a content provider, which we, as writers, know is both a blessing and a curse. When there is no editor or arbiter of what gets published, the quantity of material goes up and the quality, inevitably, goes down, especially when the publishing medium is free. Putting out a professional product is therefore most important for anyone considering using this as a promotional tool.

More here, in PDF form, along with tips on things to do if you will be in New York for the ASJA conference.