Simon, I like it and I still think the entire thing in a single page is a bit too much, but I would like to go over what Mark originally replied 'cause he did raise some valid points there (and it's been a while and I don't remember them at the moment ;-). One thing I would comment about your alternative, however, is with respect to the sidebar. Is is possible to keep it with us in every single chapter- page? At the moment we see it if we're on the front page, but as soon as we move to any chapter it disappears, and that's not incredibly friendly.
I didn't really have any special ideas at the time. But I do think the TOC should be easily accessible from any section as already mentioned. Would it be possible to have the TOC float at the side within the chapters? Actually, I'm not sure that is desirable and I've have to see it, but it does seem like switching from the main page to a chapter you get an entirely different look and feel and I think that distracts. Mark