I was always told, growing up, that defense wins championships. Super Bowl XLV was characterized by some crucial defensive turnovers, including Nick Collins's momentum-shifting pick-six on Ben Roethlisberger in the first quarter. But the final score doesn't look like a matchup between two teams that averaged 15 points allowed a game between them. Both teams finished above their seasonal scoring average, and Aaron Rodgers's three touchdowns turned out to make the difference.
Even the Packers only allowed more than 25 points twice in the regular season—against the New England Patriots and, of all times, the Detroit Lions. The Pittsburgh Steelers only allowed 30 points once, again against the Patriots. Tom Brady, the 2010 NFL MVP, did not play in the 2011 Super Bowl, so far as I can tell.
It was a wild and dynamic game, defense-wise, but there were too many times when Rodgers and Roethlisberger were tearing through defenses as advertised to say that defense won this championship. But I'll have to leave it to Sportswriter-Platitude-Busters to confirm or deny it for good; I haven't yet earned my own cable TV show, so my opinion is not final.