We need to allow proper GuidedTour localization right away. Even after bug 43143 is fixed, I don't think it's reasonable to ask translators to translate a JS file with English throughout.
We should discuss this. So far, I think the best approach is:
Wrap initGuider so you can pass in message names to use for the description and they will be served by ResourceLoader. (We need to look at how user-defined GuidedTour messages can be served correctly so mw.msg will work, and caching works right).