After some deliberation, I believe the Seahawks have the advantage here. I'm glad to see the Bus get back to Detroit, but I don't think winning is in his agenda next week. Roethlisberger and Hasselbeck were both amazing, but I think their passing games will be weaker in the Bowl. So sure, the Steelers have Jerome Bettis, but I think Shaun Alexander will be able to do more on the ground.
As far as who to root for, I have no idea. I'm already a happy man - both teams I predicted to face off in the Super Bowl are doing so. I've enjoyed watching both teams play so much. However, I'll probably side with the Seahawks this year, as their story is so much more dramatic than the Steelers, with this being their first appearance and all.