Marianne Gambelli, president of advertising sales at NBC, is leaving the company a month after Linda Yaccarino was named president of ad sales for all of NBCUniversal. Gambelli joined NBC as an account executive in 1989.

NBC is set to launch "All-Star Celebrity Apprentice," with first-season contestant Omarosa Manigault among those who have agreed to participate. Also appearing again will be Bret Michaels, Trace Adkins, Stephen Baldwin, Gary Busey, Penn Jillette, Lil Jon, Dennis Rodman, Dee Snider, Marilu Henner, La Toya Jackson, Claudia Jordan, Lisa Rinna and Brande Roderick.

"The Late Show with David Letterman" band leader Paul Shaffer may leave the show when his contract expires in 2014, he told TV Guide Canada over the weekend. Letterman's 62-year-old sidekick said that he's "going to be certainly ready to lie down after [30 years], take a nap." He's been with Letterman since 1982.

Actor Gary Collins, best known for hosting the Miss America pageant during the 1980s, died over the weekend of natural causes. He was 74. Collins starred in “The Sixth Sense,” a 1970s tv show, and hosted “Hour Magazine” in addition to his pageant duties.

USA Today has named Michael Safran senior vice president of sales, effective Oct. 22. Safran was most recently associate publisher at Time magazine.

Atlantic Media has promoted AtlanticLIVE president Elizabeth Baker Keffer, giving her additional responsibilities as president of QuartzLIVE and senior vice president and group publisher in charge of live events for all of Atlantic Media. Baker Keffer will continue to be based in the company's Washington, D.C., office.

American Express Publishing has made two moves, naming Steven DeLuca senior vice president and publishing director for Travel + Leisure and Jay Meyer publisher of Travel + Leisure, reporting to DeLuca. DeLuca is also publisher of Departures and Black Ink, and Meyer is associate publisher at Food & Wine.

Livingly Media, which runs the web sites Zimbio.com and StyleBistro.com, has brought in Martin Strohm as senior manager of marketing solutions. Strohm joins from Meebo, where he was senior manager of ad precuts.

Jonathan Hills has been named vice president of brand experience at iVillage, a new position at the company, beginning Oct. 29. Hills was most recently general manager at AllYou.com.

Jon Greenwood has been named president at Ipsos MediaCT, a digital media analytics company. Greenwood was previously global president at Media Innovation Group.

President Barack Obama will guest on Comedy Central's "The Daily Show with Jon Stewart" this week, appearing on Thursday’s episode. Obama last appeared on the show in October 2010.

Lifetime has added Valerie Cruz to the cast of "The Secret Lives of Wives," its drama pilot based on the Iris Krasnow novel. Cruz most recently appeared on the medical drama "Off the Map."

Michael Mosley, Kevin Daniels, Jessica McNamee and Kevin Bigley have all joined USA's "Sirens," its comedy pilot from executive producer Denis Leary. Leary will co-write the pilot with Bob Fisher, who is also an executive producer.

Tags: Bob Fisher, Elizabeth Baker Keffer, Iris Krasnow, Jay Meyer, Jon Greenwood, Marianne Gambelli, Martin Strohm, Michael Mosley, Michael Safran