I vote for a weekend. I've been looking for a good opportunity to make it up to Zurich to hang out with the folks from this forum, and this would be a perfect reason to make the trek up from Lausanne. For people like me, I'm sure that the weekend would be preferred to midweek. Accomodation might be an issue for some people, but I think that many would be like me and have friends in Zurich that they could crash at (who may be persuaded to come along, too).

Not knowing German or Zurich, I don't think that I can offer much in the way of assistance, though, sorry.