Personally I just don't see how anyone can be too confident in this one. Possibly the Under? Here are just some of the variables imo:
1. Weather - Obviously high wind/cold would favor Seattle
2. Styles - Seattle has a great secondary but I've watched them many times and they grab like a priest in a room full of alter boys. If they let them play Denver is in big trouble! If they call everything (which is a little more likely imo) then Seattle will struggle.
3. Percy Harvin - The guy just has another gear like a DeSean Jackson that few players have. He's barely played and always hurt but 1-2 big plays could swing the game.
You don't see SB opponents with such different styles very often and it could be a great game but I see a 1 score game that could go either way. I did hit the Over easily last year with Balt/SF but 47.5 is a tough number too. I lean Under but Seattle presses the WRs so much that Manning will have to throw it downfield more than he has. He was pinpoint vs KC on atleast 5 throws of 30+ but the wind wasn't a factor at Arrowhead that day. Personally I just see this one as a game to sit back and enjoy!!