More Genius?
Why not make ipodder a P2P software? But instead of allowing anyone to share anything (which could lead to legal issues) you could use some sort of list of approved files for trade. This approval list could "easily" be created with some sort of XML file that is updated when a podcaster pings ipodder.org. From that point aggregators could start downloading from the podcasters server and then share the file for other podcasters to download. (BT anyone?) Talk about kick ass fast and then no worries about server bandwith.