John King is the next head likely to roll at CNN. We hear that former “American Morning” cutie Soledad O’Brien, who’s been contributing special reports for the network, filmed a pilot last week for a show that would replace low-rated “John King USA.” “It won’t be a straight political show,” an insider said. “It will be more a nightly news show driven by all different topics including entertainment.”A CNN rep said, “Our development department shoots pilots all of the time.”