MacJournal 4 was recently released with podcasting support. This is great news, except that many reviewers don't think much of how it was implemented.
Not being a Mac user, I don't have any experience with MacJournal, but as near as I can tell it has been a blog client to date and the newest version stretches that a bit to include support for audio files.
However, it seems that neither the podcasting functionality nor the blogging functionality is up to par. I've pondered before and I'll do it again - why does anyone want to take on Garageband? I'm all for choice in the marketplace, but it seems financial suicide to take on the Apple behemoth.