Sawyer's 'GMA' Swan Song Begins

Diane Sawyer confirmed the worst kept secret today on Good Morning America - this will be her last week on the show.

“I’ve calculated -2,881 shows,” Sawyer said. “Roughly.”

This week, the show will look back at Sawyer’s numerous GMA gets and highlights.

Sawyer will officially take over at World News in January. ABC News has yet to announce her start date there. But sources say she plans to anchor the evening broadcast on Dec. 21 and 22.

Charles Gibson’s swan song at World News comes next week.

Robin Roberts, Sawyer’s co-host, called Sawyer “my Thelma.”

During an appearance on GMA this morning, Fox News host Bill O’Reilly, there to promote his new book, observed, “Just for getting up — you guys get a B+.”