As a Steeler fan it's hard to know what to think. This is basically the same team that took down the AFC last year, fully healthy, but they looked like 5 years older.
Keisel and a healthy Aaron Smith were both routinely blown off the LOS and that was the one thing you never saw during the last decade, Lebeau could always do whatever scheming with the back 8 and trust the front 3 weren't getting moved by anyone.
I want to say fluke and they'll bounce back next week and crush the Seahawks, but when age catches up it can catch up quick and it could happen to a lot of guys on that D at the same time.
Also fun fact of the morning,
the last time Seattle played in Pittsburgh for their home opener they beat the Steelers putting up 29 points without scoring an offensive touchdown. Not likely to happen again but not out of the question for Leon Washington and company.