"Today didn't feel like the first day of school. I mean in a great way," Kotb says of her first day as the permanent co-anchor of Today. "It just felt like it was meant to be like this."
Kotb recalls that when she was offered the role, she felt no urge to "tap the breaks at all" on taking the job. Meanwhile, Guthrie says Kotb always had her vote.
"She stepped up right in and said 'yes.' I think we are just so profoundly lucky to have each other, to be in this moment together," she tells ET. "It feels natural, it feels like this wonderful new thing that also feels familiar and I'm just really happy and excited about the future."
While Kotb's workload does seem daunting at first, she's not concerned about balancing her time with Guthrie and co-hosting the final hour of Today with Kathie Lee Gifford.
"The thing is we [Guthrie and I] share duties from seven to nine and it's a partnership," she explains. "For me... I was joining [Today] at 7:30 [a.m.], so I've just sort of moved up another 30 minutes. I don't think it changes my entire day so much."
Kotb -- who is mom to 10-month-old Haley Joy -- adds, "We have our priorities straight, Savannah and I. We know what matters at the end. ...Our kids are first and then this is a show that we love and pour our hearts and soul into. I feel the balance."
Both women kept mum about the news until Tuesday morning, and Kotb says she was thrilled to finally tell her mother, Sameha Kotb, and tried several times to call and tell her before the announcement was made. She finally got a hold of her at 8:30 a.m.
"There are certain things in your life that you don't think will ever happen, but if you do, you want your mom to witness it and say like, 'That's my kid,'" she muses. "I think that was the thrill of today."
Guthrie and Kotb also opened up to ET about how Lauer is doing since being fired from Today over sexual misconduct allegations. Kotb even revealed the text message that she received from her former colleague.