Breaking: Gibson to Anchor ABC's World News Tonight

ABC News has announced that Charles Gibson will be sole anchor of its evening newscast. His new assignment will take effect on May 29. He will continue as a co-anchor of Good Morning America until June 30. Current anchor Elizabeth Vargas will step down from the post for maternity leave. Her co-anchor, Bob Woodruff, is still recovering from injuries sustained while he was reporting from Iraq in January.