This is definitely an interesting discussion.

Rolling resistance should be a non issue either way because a lot of treaded tires only have a treaded pattern along the sides and not along the center, like the Conti GP4k for example. I agree that tread does nothing for slick/wet roads, but I do wonder if it helps for cornering on dry roads. Does a herringbone or other pattern help the tire "bite" into the road when cornering at speed? If roads were as smooth as glass then I'd say no, but since roads have grooves and cracks between each pebble it does make me wonder.