I'm not worried about anything in particular, because the Bears don't beat us with anything in particular. Instead, they lead us into some kind of twilight zone where the Packers lose all sense of time and space and start making stupid plays. Fumbles, interceptions, blocked field goals, you name it.
If the Packers come out confident and play their own style of football, and more importantly, KEEP PLAYING THAT WAY, they should win this game by a couple of touchdowns or more. The Lambeau Field crowd will be going crazy and the Bears' secondary is a mess because of injuries. This is the Packers' game to lose, but if they falter, the Bears will be right there to snatch it away.
Players to worry about are Devin Hester (on punt returns), Jay Cutler, and Greg Olson. I won't mind if the Bears put together a couple of long scoring drives, but I think the Packers can hold that offense to 17-20 points. If they do that, the Packer offense should provide plenty of points for the win. But if they allow big turnovers and big punt returns, it will be a whole other ballgame.
Prediction: Packers 38, Bears 19