This is going to be where the game is decided. It's kinda like the "irresistable force/immoveable object" thing.
On the one hand, Arizona hasn't faced a defense like Pittsburgh. As mentioned, the Steelers' blitzing packages are well-disguised and effective. They sniff out holes through the offensive lines, and are rarely slowed down by blocking backs.
On the other hand, blitzing a team with multiple deep threats and weapons is a risky endeavor, even if disguised. Warner's used to it, and has one of the quickest releases in the NFL, and his ability to read defenses is underrated. Fitz can't be covered one-on-one all day by anyone. Boldin's just the kind of distraction/decoy/surprise that could confuse the Steelers right now. Who knows how he's gonna play?
What's going to be interesting is how it goes when Pittsburgh has the ball and Arizona's on defense. Which Arizona D shows up? The one from the regular season, or the one from the playoffs that shut down the league's #2 and #3 running games and made one of the best receivers in the league, Steve Smith, a non-factor? That'll be the big difference maker right there.