I saw Petrino's offense described as a one-back pro spread which i think is accurate. They are more one-back than 2 and with a guy like Mallett i think more "NFL" routes were used because he had the arm. Definitely pass first but not a shotgun throw it 60 times, more pro style with outside zone runs and bootlegs but they run a lot of shallow cross stuff which i think is more prevalent in college.
Ole Miss and UGA seem to be throwback offenses. primarily I-form or Ace. Nutt offsets this with the wildcat but UGA seems to rely on players to make the system go. It doesnt look like they try to outscheme or alter much, have a line that can blow people off ball and take deep shots with guys like AJ Green
Bama i think is close to an east coast type offense. dont really use a fullback but run first, to set up play-action and they stay within the system
I agree with the vol fan, kiffin was pro-style and cheney has added some spread stuff to it.
I think some offenses are about system like the spread at moo state or malzahns spread, its principles and formations, shifts etc but with guys like petrino and spurrier, its their ability to call plays and press the right buttons in rythym and attack a defense.