I don't see how this is different from a Google doc, where you have one doc owner and you can set permissions so that other people can view, edit, or only leave a comment?
(wow this was painful to find)
http://www.youtube.com/watch?v=tPtJd6AzU8c&feature=youtu...
That style of fun product demonstration would be perfect for this type of app.
Also google docs now work offline really well and across multiple devices, which is incredibly useful.
But what I've found with Google Docs is that if someone is making a trivial change (like correcting a typo), they'll just go ahead and make the edit in the doc. If they're suggesting a substantial change, they'll add the suggestion as a comment and let the author decide whether to incorporate it.