@davew So Textcasting is:
1. Rich text of the kind that can be generated by e.g. Markdown (presumably rendered as HTML),
2. Of arbitrary length (author decides), optionally with titles,
3. Editable after the fact,
4. Optionally with enclosures (referenced attachments),
5. Distributed to subscribers, presumably via RSS.
I feel like this might be something you already helped invent and popularise! Textcasting is... blogging!
I'm all in favour of more people doing it, of course, and if calling it "textcasting" makes that happen, that's cool. But I'm not sure this is actually something new...