Deadline: AT&T and Peter Chernin’s joint venture, Otter Media, has promoted Sarah Harden to president, which positions her to be a key player as the telco prepares its big push into mobile video. In her new job, the former EVP of strategy and investments will “drive strategy and operational activities for Otter Media in alignment with both the Chernin Group and AT&T’s aggressive growth agendas in the online video space.”