After a futher look around wikiversity (something i probably should have done before opening my big mouth), i think that the crucial difference between wikiversity and wikibooks is that wikiversity has feedback. I think that the idea behind the example module http://en.wikibooks.org/wiki/Wikiversity:Translation_practice_course is a great one. (simplified, the idea is that you translate a page from the spanish wikipedia into the english wikipedia, and then people provide peer review of you traslation, i guess you just archive the old translations and comments...).
paz e amor,
the bellman