For years now, the Packers have been one of the few remaining teams in the NFL to reliably use a fullback every year. Players like William Henderson, John Kuhn, Korey Hall, Quinn Johnson and Aaron Ripkowski have all been key role players on offense and special teams as fullbacks.
But the league continues to evolve to a more spread-out game, with less room for specialized players like fullbacks who rarely touch the ball and don't have the speed or agility to be very versatile chess pieces.
The way the Packers use the fullback certainly appears to be changing, based on the recent usage of Aaron Ripkowski and his predecessor John Kuhn.