yid18: It depends on a few factors. Is it a Sheva Brochos Breakfast, Brunch, Lunch, Dinner? One of my children specifically asked for a milchigs sheva brochos dinner as he already had fleishigs for 4 days in a row.
Joepsh: While I understand the concept of ein simcha elah b’basar u’vayayin, I have have seen milchigs at a seudas bris, bar mitzvah, sheva brochos and heard about a chasuna where the chosson and kallah preferred milchigs.