Just in case the ETP2 guys had not seen it, it looks like this site offers a similar service on a site wide basis--
http://www.elexio.com/products/intellisite/ . It is aimed at making a website easy to edit for anyone. As they say-- With IntelliSite, the term "Webmaster" is now redefined to mean, "Anyone who has word processing skills".
Unfortunately they require IE6 for a demo, so I have not yet been able to log in a try the demo site out. Their product might be a good opportunity to swipe some ideas that would be useful for ETP2.