Wall Street Journal: Liz Heron, a veteran journalist and social media editor, has joined the Huffington Post as its new executive editor. Heron spent the past 18 months at Facebook as the company’s head of news partnerships. Prior to that role, she logged stints at both the Wall Street Journal and the New York Times in social media positions. At HuffPost, Heron will effectively serve as editor-in-chief Arianna Huffington’s second-in-command. Her responsibilities will include oversight of both editorial strategy and audience development.