I'm a Den Leader and I've worn a kilt, Black Watch, to a Pack camp out. Folks loved it. In fact when we wrote or by-laws we left the pants option open. At the Cub Scout level the uniform is defined by the Pack By-Laws. This may be different from the Boy Scout Troop. Stillwater makes boys kilts that are on par price wise with the Cub Scout pants.
My sons own three. Also, if I'm not mistaken B-P wore a kilt. I think there is a picture of him in a kilt on a thread here.
Chris