I just saw the PodPress plugin mentioned in the WordPress dashboard feed, so checked it out quickly. What a kick-ass plugin! Totally manages podcast publishing, enclosures, web players, iTunes integration. Handles files uploaded to the blog, as well as remote files (absolute urls). Presents mp3, m4a, mov, mp4, pdf, etc... files. Very nice.
I've updated the most recent 2 entries in my podcast section, to see how it works. Pretty slick.