I believe they'll lose to the Steelers as well, and if McNabb is healthy and plays against the Pats they might give them some problems as well. It's a great accomplishment to go undefeated, but it doesn't matter if you don't win the big prize, so in my opinion it's a great accomplishment, but doesn't mean much if you don't win the Superbowl.
I think Pittsburgh will give them a run for there money. If the Steelers are healthy, and they have there regular lineup, I think Pittsburgh has a shot to beat them. Ben Roethlisberger is one of those guys that want to win, and that will do anything to win. I love that competitiveness, especially for a guy that's the leader of the team and plays quarterback.
Steelers defense always keeps them in games. And I mean always, they always keep the Steelers close into ball games. That gets the offense fired up, and they come out firing on all cylinders!