The Steelers allowed 49 sacks this year, good for 4th worst in the league.
The '08 Steelers have given up more sacks than any other Super Bowl team in the past 10 years. They've given up the second most in the past 20 years, with only the '98 Falcons surpassing them. That Falcons squad ranked 6th worst in their year, thus leaving the Steelers the worst ranked sacks-allowed team in a Super Bowl.
Twenty years is a good cutoff. It's a round number, and closely approximates the league-wide shift to shorter drop-backs and timing routes (informally, the West Coast Offense).
Much has been made of the Steelers' O-line problems. (Their 3.7 ypc is also 4th worst in the league). We don't seek to assign blame. A sack isn't a definitive indictment of the line; in this case everyone knows Roethlisberger has a penchant for holding on to the ball. We simply mean to provide a historical context to show how unusual it is for a team that gives up so many sacks to make the Super Bowl.