I am a numbers junkie, doing some preliminary number crunching and I have found the following:
Since I started tracking this (I put my chart together before the Steelers played the Seahawks in SB XL) the team that has the better winning percentage amongst common opponents is 4-1. The only team that had a better W-L and lose is Patriots vs NY Giants.
The NFC has not won back to back Super Bowls since 1996/1997
in 2006 Pittsburgh chose to wear their road white jersey and won
in 2009 Pittsburgh wore road white due to NFC being "home team" and won
in 2010 Pittsburgh will wear road white jersey due to the NFC being "home team"