Viacom unit head overseeing MTV, Comedy Central to leave

By Liana B. Baker and Jessica Toonkel SAN FRANCISCO/NEW YORK (Reuters) - Longtime Viacom Inc executive Doug Herzog, who oversees the networks Comedy Central and MTV, is leaving the company next month, according to a memo to employees sent Wednesday from chief executive Bob Bakish. Herzog, a 25-year veteran at Viacom known for helping develop such MTV hits as "The Real World" and Comedy Central's "The Daily Show," is leaving as part of a restructuring following the appointment of Bob Bakish as ch