How if your Duke do you consider replacing McCallie? Who do you hire that would have the level of success that she has had? Muffett and Walz aren't leaving their respective schools as the schools would match whatever Duke offered. Plus Duke wouldn't be a step up for either coach with the success the coaches have had.
Now do I think McCallie is the right coach to get Duke a National Championship. I'm not sure, but based on her tenure at Duke, my leanings are no she's not. But I get back to the question, who do you hire? Now if Duke could pry Kim Mulkey out of Baylor, that would be my first choice. But then would Kim's sideline antics fit Duke's Academic Culture. She would fit the Duke Students and they would love her, but would Coach K and the Athletic Department? If Kim was coaching the current Duke players for a couple of years, they would have given both ND and UConn a tougher game and wouldn't surprise me if they don't win at least one if not both games since they were held at Duke.
I think Duke is stuck with McCallie as she'll have the level of success that will make it difficult to fire her. Now if a Big Money Donor Booster gets involved which usually doesn't happen with Women's Basketball that could change. She's also young enough so there still is time for her to get Duke a National Championship.