If enough people appear to have similar questions in the readings, the instructor will see this as a sign to spend some extra time the following day in class clarifying the points of most frequent and/or serious confusion.
I really hope this occurs frequently throughout the quarter. I think it's really cool that us students can have an impact on what content is being reviewed during lecture, and I think that this will not only motivate students to be active on discussion assignments, but it will help content understanding as well.