As AmeriConn pointed out, TAMU has been a real positive surprise this year. To me, Tennessee, South Florida, Michigan, and South Dakota State have also been. Mizzou State is about where I expected them to be, but Hamilton has done a great job in her first year (as has Kellie Harper after departing Mizzou State).
That's what I'd use as a criterion, but the committee doesn't usually think that way. I still can't get over Geno being National Coach of the Year Stewie/Moriah/Tuck's senior year. Yes, they were undefeated, but that team didn't really seem to need elite coaching to win. Then the following year, when UConn exceeded all expectations, they presumably didn't want to give it to him two years in a row.