I got a chance to look at Barley's inline editing plugin for WordPress and honestly I was disappointed. I don't think it is really an inline editor, in fact there are currently several much better inline editing plugins available in the repository. Barley does not have enough editing options available at the moment. Users can not even insert an image in a post (they can set featured image). I think it will need sometime to become a good product. It does have potential to be one, but right now it is not.