You don't ignore Alex Poythress and Willy Cauley-Stein but the key player in this team will be freshmen Julias Randle who rivaled Andrew Wiggins for best incoming player (Riggin' for Wiggins or Riggin' for Randle works for me Bucks). The Harrison twins, C Dakari Johnson & SF James Young were all top-10 recruits as well as future pros. The depth on this team will be incredible. Talking undefeated is a bit much but this group is way closer to 2011-12 than last year.
Also, keep an eye on this kid, Derek Willis a 6'9" freshmen who has looked good thus far for Kentucky, according to various reports.
Florida is good but they have issues keeping kids on the floor for a variety of reasons. It's easy to hate Calipari and Kentucky. This year, though, I think it's going to be tough if you don't like them because they are going to win a lot.