This would be incredibly useful for blogging on SN, especially for posters like @siggy47 and myself via @lain (if I get off my ass and find some time to write, lol) if updates to longform content are deemed necessary.

Some of the suggestions here, including making permanently editable posts cost more to publish (and maybe even revise), are good to establish middle ground with this type of thing.

It just needs to be done correctly, with edit history and reasons being absolute priority.