Sunday game between the Eagles and Green Bay.  
Everyone is picking Green Bay to go to the Superbowl and the Eagles to be an 8 & 8 team at best yet the spread is only 3 points,  What am I missing?

Point spreads are not based on how many points oddsmakers think a team will win by, they are set to get the most even betting action.  The perfect point spread occurs when the same amount of money is wagered on each team.  Since the house gets a piece of the action on every winning bet (and obviously keeps all losing bets) , they make out pretty well.