Nope, rules will not extend beyond the column boundaries.BTW, can it be done paragraph rules to span to frame (in columns layout), Just to make a table effect? Like in the MikeWenzloff's example?
RE spanning columns. If Quark decides to allow text (hence a rule) to span columns, I certainly hope they do a better job of it than Adobe. Well, "better" isn't the proper wording. More efficiently would be a better term. In ID when one spans columns it can horribly slow down ID once there are very many spans. So much so that I never use the "feature."