Tennessee has a rabid fan base, an outstanding stadium, good facilities, plenty of money, the SEC, the East Division---inherently more winnable than the West---, and a decent tradition. They're a state's flagship school and there no reason they can't be a contender for the SEC East, SEC, and national title.
Auburn suffers from being the "other" state school, an both Auburn and Arkansas will always have to get through LSU and Bama to get a division title---add Miss State and A&M as of late, and a surging Ole Miss coming up, too. I guess if the SEC adds two to the east and slides Mizzou over thatll give the West a "Kentucky" caliber win.
Boston College is a middle of the road ACC school. And the ACC's future is uncertain. Purdue is a Bleh Big Ten school that has earned little respect. Cal is a good gig, but not a marquee football program. That's a building job that could make someone's career. Colorado is just terrible. NC State would be very good IF added to the SEC East--otherwise the ACC's current instability will be a ball and chain in a coaching search. Kentucky, lastly, is Kentucky---a basketball school in a football conference.