I am now in communication with the professor and other TA, for the class I'm TAing this fall (actually, it's a full year course; I also TA another course next semester). The prof sounds great, we're meeting this week, and he's getting us to lead discussion groups! Hurrah! I love discussion groups.
My dilemma: the class takes place during my German course. I just e-mailed the prof and asked him if discussion groups take place every week, or how this works. This may have decided my quandary over whether or not to register for German, or whether I should audit (and therefore not have to worry about missing quizzes, etc., when I'm being a TA).