Hi Jason, you have the same intention like me.Exactly like Mike Kamermans I would like to define the contents of the book via a standard list (ul or ol) with links to the wiki pages (see http://grammar.nihongoresources.com).
An special plugin should parse this TOC and export all contents (linked wiki pages plus the toc-page) as modules (topics/information unit) to XHTML. An individual XSLT transformation could generate one great XML-File of the whole book. This file could process to the formatted book (for example, via XSL-FO/desktop publishing systems).
Additional advantage: Wiki syntax is no good base for the cooperation with translation agencies in contrast to XML. If I export the contents of the wiki pages to XML, I can have it translated and transform them again via XSLT in wiki syntax. In addition an Import-Plugin to DokuWiki would be helpful (other job;-)).
An other way: see also "bookcreator" plugin from Luigi Micco. Kind regards Jörg -- DokuWiki mailing list - more info at http://www.dokuwiki.org/mailinglist