NEW YORK (AP) — Diane Sawyer signed off as anchor of ABC's "World News" on Wednesday, telling viewers that it has been wonderful to be the "home port" of the network's news team each weeknight. The 68-year-old Sawyer, one of television news' best-known personalities, has anchored ABC's flagship newscast since December 2009. On Wednesday's newscast, she chatted briefly on the set with Muir and took viewers on a behind-the-scenes tour pointing out people who worked at "World News."