One thing that we at Wikibooks have been kicking around for a while, but have not been able to get developed, is some kind of system for extracting metadata from the pages of a book (word definitions for a glossary, references for a unified bibliography, keywords and terms for an index, etc) and displaying that data on a separate page. Think about our tags, but instead of having the references appear at the
Anyway, if you have some spare time today you should head down to the Kids Open Dictionary project and take a look around. Their project is all PD, so content reuse in Wikimedia-world shouldn't be a big problem. I wonder if some kind of synergy would be possible between them and Wiktionary? Maybe we could get some of our precious few Wikijunior enthusiasts interested as well.