Danny takes up the 'whither podcasting' discussion in a reasoned manner. He hits on some of my hotspots (no good metadata, no good linkage, often middling content). He doesn't hit on my other bit, the lack of scannability, searchability, archivability and referenceablility that we presently lose in an audio medium. Some thoughts on that are percolating, but not in a directed manner. So in the meantime, read Danny....
Besides which, anytime someone namechecks Peel, 'tis usually good.