Render to plain text

It would be nice if there was an easy way to just render the whole thing to plain text, especially for text-to-speech, or performing diffs. I know there are ways to strip out tags from the rendered HTML, but given there's more metadata in the clean json it might make sense to provide an API way of retrieving this more accurately.

EDIT: Or how about extending the API so that each plugin can render to different formats, and have HTML, plain text, markdown, or even MediaWiki as render options?