Ori pointed me to https://en.wikipedia.org/wiki/Wikipedia:The_Wikipedia_Adventure (prototype at http://en.wikipediaadventure.org/).
It's basically a game that walks you through becoming a Wikipedia editor. It has its own rough tour library, but it seems like they could use GuidedTour to great effect.
The code (http://en.wikipediaadventure.org/w/skins/common/tutorial.js) is under the public domain, so we might be able to use some snippets as well.
The script is pretty elaborate (https://en.wikipedia.org/wiki/Wikipedia:The_Wikipedia_Adventure/Script)
Matt Flaschen