How does a community get a creative momentum

I have been quite active on the We Are Smarter Than Me website (see link on the right). One of the issues tht I have been interested in is how does one rekindle the interest of the members of community who have joined in anticipation of being part of the writing group. The effort is similar in intent to that of Charles Leadbeater's We Think (http://www.wethinkthebook.net/home.aspx) but the execution makes it much more difficult to accomplish this task.

My difficulty is that the whole direction of the project, while noble and clearly with merit, lacks sharpness necessary to reign in contributions from many sources. However, I have plunged to be the first to take ownership of several Chapters as Moderator to see how I can move the actual content generation on.

What bugs me is the comment in Value Networks exchanges that Community is a worthless term. I have to exploire further.