"I'm just so glad it's official," Roberts said. "It's a real work in progress. The timing had to be right. It's not something I looked for, or asked for, but I'm raring to go."
Roberts is expected to continue as news anchor, a post she's held the past three years, the New York Daily News reported Tuesday.
"Diane and Charlie are workaholics," Roberts said. "If I can do anything that will help with their workload, then I'm doing my job."
Roberts began her new duties Monday.