When I'm asked how to stop Aaron Rodgers and the Green Bay Packers, I've got no answer. Right now, Rodgers can't be beaten and teams have to focus on outplaying them in every other aspect of the game.
The Packers have always had some weaknesses on offense that could be exploited, but no defensive has come up with any scheme that's even slowed Rodgers down. His game-by-game stats are a model of dominant consistency. The only two things that have stopped him have been dropped or tipped passes (not something opponents can game plan) and keeping the offense off the field.
Matt Bowen at the National Football Post did a great job of breaking down every major defensive scheme in the NFL, and how effective he thinks it would be against Rodgers. The results weren't promising for defensive coordinators. From NFP:
Zone pressure in both my base and sub packages with some Cover 1 on third downs and inside of the 10-yard line. I want to mix my coverages throughout the ball game, but when I need to make a stop and give my offense a shot, it is going to be the Tampa 2 defense.
Easier said then done, but this was my long answer thinking too. Mix up the defensive scheme, rely on the zone blitz to vary the passing lanes, and rely on Tampa 2 as your single best scheme.
Lovie Smith and the Bears caused Rodgers a lot of problems in their final two games of the 2010 season with their Tampa 2 defense, but he lit them up for 297 yards, 3 touchdowns and only 1 INT in their game back in September. That's a great game in it's own right, but it's also his worst passer rating (111.4) in any game this season. And that's the best any defense has done in 2011.
The entire article at the National Football Post is good, and it's recommended reading.