I used to belong to a Lutheran church where sermons always seemed to begin with jokes, cheesy object lessons, or cutesy stories, and they ALWAYS seemed to undermine the death and life nature of Law and Gospel sermons.
Everyone had a good chuckle and relaxed, as nothing serious was to follow. (Do the professors at St. Louis actually teach their students to do this? Seriously. Do they?) Beginning sermons in this way seemed to be an attempt to be a good old boy and 'relevant' in an appeal to some country club style of populism.
Every Christian should be required to read Neil Postman's Amusing Ourselves to Death and consider how the terrible state of public discourse in our country might be influencing the pulpits in our churches!