Some thoughts (from a non-developer):
Please consider including a section on intra-zone cross referencing between conversations (as for templates, for instance--one set of templates in one conversation, and then use the insertTemplate macro to maintain consistency across a zone.) Now, you may consider it obvious from the macros which exist, but it wouldn't hurt to make it explicit. There's so much to grok that I think you'll want to 'help' the developers in making certain connection.
Under Appendix-RSS and other XML Formats, you can now include a section on OPML!
(since the addition of the new date macros).
Consider including a separate section under security for Transport Layer Security, so that a developer scanning the TOC would see that right away, instead of having to dig for it.
Consider section within CSS on limitations. Specifically, when order of css elements is important, it may be best to use an external stylesheet editor and not store the style sheet in Converersant. (please correct me if I'm wrong on this.)
Event calendars? (very powerful, I think).
Add Plugins-->Overview-->Community-produced (hopefully this section will become larger with time).
Something about pre-bound url's (/signup, for example). To be clear, what I mean is url's that yield a page without having to define it in the siteStructure.