I don't think the Colts have an Offense that can move at will. So far this season I have seen the Colts sucks in the first half of many games when they face a solid-great defense. However, by the 3rd and 4th quarter, the opposing team's defense is warn down (because their offense sucks, the D is on the field all day. Indy hasn't faced a good offense yet) and the Colts are able to move the ball more effectively because of it. That is why you see the Colts in a tight game through the first half, and then blow them out in the second half.
Now that the Colts have to face the best defense in football AND the best offense in football, they won't be able to do that. Our offense will be able to move the ball at will, which will mean our defense won't be on the field too long. If we get a lead (which we will), Manning simply won't get enough possessions to make a comeback.