Well, this is a tough one. A regulation NFL game has 60 minutes of playing time, broken down into two halves of 30 minutes and four quarters of 15 minutes. However, there are a number of stoppages a long the way due to various rules and timeouts. Plus, there's the 12 minute halftime. The whole affair usually takes about two and a half to three hours.
But, that's for a regular NFL game ... this is the Super Bowl. The playing time is the same, but you can expect the halftime show to go for about 30-45 minutes. Plus, because of all the commercials, you can expect the breaks between plays to be a bit longer too. So, while it's hard to pick a number, you can probably expect the game to take about four hours — that's about three and a half hours of game play/stoppage/commercials and about 30 minutes for a halftime show.
Another player to pay attention to on Sunday is Richard Sherman. The Seattle Seahawks corner back garnered a lot — and I mean a lot — of attention after the NFC Championship win. But besides being a talking point for everyone everywhere in the past two weeks, he's also an amazing football player. Watch out for him to be a major threat to Manning and the Bronco's passing game.