Will fans watch Couric at night?

Like a lot of Katie Couric fans, Donna Frechette plans to show some love and tune in when the ''Today" show cohost makes her big debut as anchor of the ''CBS Evening News" in September, a move that has long been rumored and that was finally confirmed yesterday.

''I love her personality. I can totally relate to her," says the Quincy resident.

Long-term, though, Frechette is pretty sure that most nights she'll be watching Elizabeth Vargas on ABC's ''World News Tonight."

''Elizabeth is more serious than Katie, which is appropriate in the evening. Katie's going to have to really tone it down now," she says. ''She's not doing quirky segments anymore."

CBS News has invested its future in Couric, with a multiyear contract, a managing editor title, and the opportunity to contribute to ''60 Minutes" and anchor some prime-time specials as well. But a number of Boston-area residents interviewed yesterday said they remain noncommittal about the ''CBS Evening News With Katie Couric."

''I think she's adorable. She's so cute. But the evening news needs a serious person. They have a dress code, you know," said Margaret Barett, a Milton resident who was walking on a treadmill at Fitness Unlimited yesterday. ''If you had said Ann Curry, I would have said 'Yes!' I like her a lot. I don't see Katie on the evening news."

Helene MacNael, a Dedham resident and retired teacher who was finishing up a manicure at Fancy Salon in Dorchester, was adamant about her decision not to watch CBS. ''This is Walter Cronkite's seat we're talking about. To have Katie come in. . . . She has some big shoes to fill. Just because she's perky doesn't mean it will fly. She's really going to have to take on a different persona."

Nationally, of those asked if they would rather see Couric in her longtime role as ''Today" host or as the first woman to anchor a network weekday evening newscast on her own, 49 percent favored the morning and 29 percent said evening, according to a poll conducted this week by the Associated Press and TV Guide.

To be sure, Couric won't be the first anchor to make the leap from ''Today" to the evening news. Both Tom Brokaw and Barbara Walters have done it.

Yesterday, CBS News executives were gushing in a statement released to the media. Leslie Moonves, the president and chief executive of CBS Corp., cited her charisma and fame as qualities that will contribute to the news operation. ''I am personally so excited," said Moonves. ''Katie is simply one of the best in the business."

Rome Hartman, executive producer of the ''Evening News," said that ''the same qualities that viewers have appreciated for Katie's entire career will make her great: honesty, openness, integrity. Finally, what people appreciate most about Katie is that she's real -- that's really her up on the screen. I cannot wait to start working with her."

When she faced the camera yesterday on her 15th anniversary on the program, Couric revealed what she called ''the worst kept secret in America."

''After listening to my heart and my gut, two things that have served me well in the past, I've decided I'll be leaving 'Today' at the end of May," she said. ''It was really a very difficult decision for a lot of reasons. First of all, because of the connection I feel with you. I know I don't know the vast majority of you personally and it may sound kind of corny, but I really feel as if we've become friends through the years.

''You've been with me during a lot of good times and some very difficult ones. . . . I can't tell you how grateful I am for the support you all have given me. . . . Another reason that this decision was so difficult is my relationships with the people on this wonderful show. . . . The notion that we're a family is not just some cheesy promotional device. I really care deeply about the people here, from everyone who works behind the scenes to the faces that are familiar to all of you, like Al and Ann and, of course, Matt."

Couric added that she believes change is good. ''Although it may be terrifying to get out of your comfort zone, it's also exciting to start a new chapter in your life. So for now, it's not goodbye -- at least not yet -- but a heartfelt thank you."

Lauer responded immediately with his typical wit. ''Also coming up in this half hour . . ."

He added that despite mixed emotions, he was ''thrilled for the fact that you're taking on a new challenge."

Well aware that Couric had not announced where she was going (media reports had predicted that the CBS announcement would come later), Lauer leaned over and flipped through Couric's script. ''Oh, and did it say anywhere in there where you're going?"

The bold move prompted lots of laughter on the set.

''At this point, I'm thinking of opening up a second-hand bookstore in Montana," Couric joked before finally revealing her CBS position.

Curry summed up the moment by saying, ''It feels like my sister is going off to college. I want to make sure you've got your toothbrush, your bags packed. Oh, but I'm so excited for you."

Couric made clear in her speech that the 54-year-old ''Today" show has always been bigger than one person.

Pat Hayes, a Boston firefighter who lives in Hyde Park, agrees.

''I'll still watch the 'Today' show when Katie leaves," he says. ''I'm pretty much an NBC person."

And yes, out of curiosity, he says, ''I'll check out Katie on CBS. She has a big following. The only thing is, can she make the transition? I don't know."

Suzanne Ryan can be reached at sryan@globe.com.