Superbowl Upset?

The Giants and Patriots played each other 5 weeks before they met in the superbowl. The game was very competitive, with the Pats winning by just 3 points. Given these facts, can someone explain to me:

1. why the entire sports journalism world is calling this an upset; and even more ridiculously
2. why there is even debate on where this sits as one of the greatest upsets of all time?

I guess the answer is that logic, and prior football knowledge is secondary to outcomes that simply disagree with the media-induced frenzy that is the superbowl hype-machine.