I think the defense the wild card in the rematch... in the early weeks of the season the defense was still trying to figure out the new system they were going to go with and did settle in until maybe the 3rd quarter in week 2. In the fail Mary game both defenses basically stop the offenses.
The the Cowboys were able to run on the Packers still this last week but they have what has been called the best OL in the NFL and very good weapons receivers which the Seahawks don't, thought you need to watch out for them still the Packers can probably get a lot more aggressive against the run.
Also the Packers offense didn't get going until after week 3... even Rodgers, Cobb and Lacy looked rusty to start the season. .. only Nelson looked reany to go early on