Eh, I don't see it as a limitation of RSS, it's still up to the aggregator to display the episodes however they want after they've fetched the raw data.
This. An RSS feed of .mp3 or .ogg files is all I need for all of the formats mentioned by OP. It is annoying that some podcasts don't have RSS feeds -- this is what feels like a step back to me, but it's fundamentally a choice of the author/publisher. I'm much less likely to consume a podcast's backlog if it's not available as an RSS feed, and if the only obvious way to play content is through an embedded player or app that obscures the source media I probably won't play a single episode.
Interesting question. I've seen collections of audio content claiming to be podcasts that don't have RSS feeds, so the term is definitely used that way. Whether that makes it a valid definition is open to interpretation, the word is pretty new still. Merriam-Webster seems to think that an automated download mechanism is required, though it doesn't specify RSS in particular:
>a program (as of music or talk) made available in digital format for automatic download over the Internet
I can see arguing that this doesn't even rule out walled-garden streams with an auto-play feature, since streaming and downloading are functionally the same (the only difference being what type of memory the data is stored in, and swap memory destroying that distinction entirely).
