Apple - iTunes
I have yet to figure out a use for iTunes "podcasting". My commute just isn't long enough, and there's no other time I could listen to something that requires processing. I also don't usually want to listen to such things more than once, so the permanence of a podcast file is a bit odd. Not to mention I prefer things like lectures from The Teaching Company or audio books for that sort of setting.
iTunes radio is another story. One no-one talks about. When iTunes first came out they offered very few low bit-rate stations with poor reliability. Now there are hundreds of 128 kb stations, and they actually work. You can drag and drop to playlists (need to display the comment field in the playlist view or you only see the station ID) and add your own metadata (rating, type, etc - I unchecked most of the default iTunes columns as they're not relevant to radio). I suspect you can create smart Playlists from this data.
I'm listening now to KCRW. Very good.
I wonder when anyone will notice iTunes Radio now spanks the competition?