Didn't you say you were reserving spots for 2 weeks or so? There's still time...I think. In the meantime, I'd recommend we establish a posting schedule; that helps keep people engaged and on track (according to @RJS anyways). Personally, the "one post per week, but continue ahead of time if people are fast" schedule works well for me, but I can go along with just about anything (including the lack of a schedule).