Caulton Tudor from the News and Observer says:
Duke has had two men's basketball teams this season.
There was the Duke team that swept the Maui Invitational, stumbled against Pittsburgh, won at North Carolina and was the nation's most impressive club for a long stretch of the regular season.

And then there was the other Duke, the team that appeared during the middle of February. It has had little resemblance to the earlier version.

Those are the Blue Devils who dropped successive road games at Wake Forest and Miami, struggled at N.C. State, lost at home to Carolina, then looked tired and hesitant during last week's ACC Tournament in Charlotte.
He concludes that:

Overall, the odds are stacked against the Duke of November, December and January staging a March encore. But the Devils are stronger than they looked in Charlotte. They'll be around for the third round
I have them in my final 4, which may be more of a heart pick than a head pick.