Kennywood did have the bumper cars open in 2011. It wasn't popular and the ice and snow made the floor dangerous.
I don't think we'll see Exterminator opening anytime soon for Holiday Lights. I'm sure the cold has something to do with that. Lost Kennywood, though, would be stunning in lights with the Whip running and perhaps even Wave Swinger.
I could see Noah's Ark being added in the near future though.