"He is passing the baton this year and staying home with his family, and they asked me if I would do this special 25th anniversary program," Andrews said Wednesday during a telephone interview from Los Angeles.
The New Year's concert in Vienna - mostly waltzes, polkas and marches from the Strauss family - has an estimated worldwide TV audience exceeding 1 billion. Daniel Barenboim will conduct for the first time in 2009, and the concert is to be released on DVD by Decca Classics.
Andrews wasn't sure whether she will become a permanent replacement for the 92-year-old Cronkite, the retired CBS anchorman.
"I'm sure the format is pretty much the same," she said. "It's like a wonderful postcard tribute to Vienna and its surrounding areas and beautiful museums and castles. I'm sort of the glue that holds the whole evening together."
Andrews plans to fly to Vienna on Friday for the start of production. She has not been there since the early 1960s, when she visited the city while "The Sound of Music" was in production in Salzburg and other parts of Austria. The picture won an Academy Award for best picture, and Andrews was nominated for best actress for her portrayal of Maria von Trapp.
She thinks that, because of the movie, many people identify her with Austria.
"Certainly for me it has wonderful memories," she said. "It seemed to make a great deal sense that I accept the baton being passed from Mr. Cronkite."
Andrews, a fan of the music of Ravel, Prokofiev, Mozart, Brahms and the Strauss family, has never been to the Musikverein, the 138-year-old hall where the concert takes place.
"As much as I will be a hostess, I will also be a tourist," she said. "I just think it's a lovely tradition. It's something that makes everybody feel good. The great Strauss music is so enjoyable, it all seems to fit in with the happiness of the new year."