Actually I generally enjoy watching Indianapolis play. It's a pleasure to watch Peyton Manning play at a level that few QBs have ever played at. Peyton is often compared to Dan Marino. It's a very fair comparison, at least in terms of talent and accomplishments. So it was nice to see Peyton beat everybody's golden boy Tom Brady. QB is without a doubt the most important position in football, but too much credit and blame are often assigned to QBs. People who thought Manning "can't win the big one" assigned too much blame to him, just like all the Tom Brady worshipers gave him far too much credit for the Patriots' success. It was all too similar to the kind of things people used to say about Dan Marino and Joe Montana.
Anyways, while it would be a little surprising to see Chicago win (or any NFC team win the Super Bowl,) it would be even more surprising to see them win because of Rex Grossman. They will clearly try to run the ball down the throat of Indianapolis. Rex also seems to have realized that he doesn't have to do so much to wins games for the Bears. They have tremendous talent on defense and solid players on offense.
On the other hand, it would not be shocking at all to see Peyton Manning as Super Bowl MVP. Chicago has been vulnerable through the air. They play a lot of Cover-2 and rely on their front four to get pressure on the QB. That will be tough to do against the Colts fast paced offense.
But hey, Florida was a big underdog against Ohio State a few weeks ago, and we all saw how that turned out... So I will predict that Rex will indeed play well and that Peyton Manning will make some costly mistakes. Chicago 30, Indianapolis 24.