—Starcom MediaVest Group: Media buying vet Renetta McCann is taking a year-long sabbatical from her post as Starcom MediaVest Group’s global CEO, citing family matters. She officially steps down on January 1, 2009 and will hand the reins over to Laura Desmond, currently CEO of SMG/The Americas. McCann assumed the role of global CEO for Publicis Groupe-owned media agency in 2005 after serving as CEO for Starcom North America since 1999. Desmond, a 20-year SMG vet, has served as CEO/The Americas since 2006. For the past year, she’s building the network’s search tools and was behind the formation of Pixel, the agency’s digital content unit.

—Cooliris: YouTube’s head of monetization, Shashi Seth, has left the company to take on the role of chief revenue office for Cooliris, reports GigaOm. At the Menlo Park, CA-based startup, Seth will help develop a new business and advertising model.

—Oberon Media: Don Ryan has been promoted to COO from SVP-publishing, where in his new capacity he will be responsible for all publishing, development and platform operations. Before joining Oberon in 2006, Ryan led the downloadable games service for MSN and Xbox 360 at Microsoft (NSDQ: MSFT). In addition, EVP Ezra Kucharz was let go due to restructuring. More details at mocoNews.net...

—NBCU’s Green Is Universal: NBCU has tapped Beth Colleton to lead the company’s “green” initiatives as VP of “Green Is Universal.” Reporting to president of women and lifestyle entertainment networks Lauren Zalaznick, Colleton will manage GIU’s business, marketing and content, including coordinating programming with all the divisions. Most recently, Colleton was the head of corporate social responsibility for the National Football League, where she worked for 15 years. Release.

—Kaboose: Alexandra Aleskovsky is joining Kaboose as GM and SVP-online media properties, reporting to president and COO Craig Wallace. Aleskovsky joins from WeightWatchers.com, where she served as GM and SVP. Earlier, she was CMO of ClubMom and GM and SVP of iVillage. Release.