New York ? Now that Tony Bennett has serenaded her with “The Best Is Yet to Come” on her final “Today” show, Katie Couric is about to find out if that’s true.

Couric heads to Las Vegas where she is addressing a meeting of CBS affiliates today, drumming up enthusiasm for her new job as anchor of the “CBS Evening News.” She’ll make her debut on that show in September.

It was a long goodbye in more ways than one: NBC has been celebrating Couric’s 15-year tenure as morning television’s leading personality almost since she announced her job change on April 5, and the final three-hour show was almost entirely Couric-focused.

“It’s a little embarrassing,” Couric said. “It’s a lot of Katie. Three hours.”

At the show’s end, she surveyed the multilayer cake with “KC” written on it and raised a glass of champagne. “To everyone in TV land, thanks so much,” she said.

Co-host Matt Lauer placed a box of tissues on the table in front of them at the show’s outset, but it wasn’t needed. Couric held it together, although one tear was spotted in the corner of her eye as “Today” talked to six people she had interviewed – an inspiring school principal, a woman brutally raped in Central Park, survivors of the Columbine school shooting and the 2001 World Trade Center attack and parents of a boy who had died of brain cancer.

Katie Couric, foreground right, with NBC Today show co-host Matt Lauer, raises a glass in a toast with cast and crew members at the end of her final show. In the second row are, from left, weathermen Willard Scott and Al Roker, and film critic Gene Shalit.

“In meeting her and talking to her, I felt that it helped heal me as well,” said Lauren Manning, who was burned during the terrorist attack.

“Today” has dominated morning television for more than 10 years, never losing a week in the ratings, and is the most profitable show on television in advertising revenue.

Couric was the biggest reason for that success. During her time on the air, “Today” fans watched as Couric, 49, grew from a chipper young reporter to a mother with two girls and a young widow when her husband, Jay Monahan, died of colon cancer. She underwent an on-air colonoscopy that encouraged thousands of Americans to do the same, which doctors called the “Couric Effect.” She called that her proudest professional accomplishment.

With Couric’s departure, NBC is shutting down its streetside Rockefeller Center studio for a summer makeover, preparing for Meredith Vieira of “The View” to take over as her successor in the fall. “Today” will spend the summer in an outside studio nearby.

Couric, whose parents and daughters watched from outside the studio, acknowledged the mixed feelings of nostalgia and eagerness for a new challenge.

“I’m feeling happy and sad and completely out of control,” she said at the show’s outset, “and you know how much I like that.”

Lauer said he’ll most remember all the laughs they shared, on and off the air.

“People talk about chemistry,” Lauer said. “I have never been able to define it. From my end it came from genuine love and respect and I’m going to miss you.”