TVNewser first reported it last week, and now it's official: "Alexandra Wallace has been named executive producer of NBC Nightly News with Brian Williams, it was announced today by NBC News President Steve Capus."

More: "Her appointment makes Wallace the first woman to lead a weeknight network evening newscast in a decade, and she becomes one of a small group of women to serve in the top post of a Big Three daily newscast."

Her appointment is effective immediately. She will continue to serve as NBC News Vice President. Bob Epstein will continue to serve as senior broadcast producer.