1) Duke also has a bye week. Defensively, they play press man and press cover 4 looks almost exclusively, which is tailor made for Ryan Willis's strengths. It will be interesting to see what, if any, adjustments Duke makes. If I was their defensive coordinator, I would use cover 4 but play much softer than the Blue Devils did last season.
2) Defensively, Duke is experienced. Their major drop off will be at linebacker. I was a huge fan of both Joe Giles Harris and Ben Humphrey. Duke looks to spill everything and keep their linebackers clean. If VT can get hats to the second level, I don't think Koby Quansah and Brendon Hill will be as effective getting off blocks.
Duke's defensive line will be a problem. Tre Hornbuckle and Derrick Tangelo are returning senior starters who were effective against VT last year. Victor Dimukeje is a big defensive end who gets penetration- he would have been a difference maker at VT and is at Duke. This will be a really big test for a neophyte offensive line. Despite Alabama blowing out Duke, the Crimson Tide did not put up huge rushing numbers despite playing with a big lead late.
3) I don't know what to expect of Duke offensively. It seems like every year they have a good pain in the ass tailback. Quentin Harris doesn't spark much fear at quarterback but he is very sound at running read option. I don't know if Duke has playmakers at wide receiver- the guys who have been problems in the past have used up eligibility. I don't know if any of the returners had a catch against VT last year. Stop the run, win the game.