I also added the WikEd editor gadget to Wikibooks a while back. I dont remember if I made any kind of a fanfare about it at the time. However, I've been using it and am very impressed by it. It's not quite WYSIWYG, but the syntax highlighting is a really neat trick. As a programmer, I've become so accustomed to syntax highlighting that I can't remember how I edited wiki without it. I especially like the full-page editing mode too. Just the full-page mode and the syntax highlighting make this cool tool worth a test. The editor has a lot of other features that I don't use personaly, but I imagine they would be useful to some people.
Next time you're at Wikibooks, check out the Collections gadget and the WikEd editor gadget. Quite cool tools.