Getting pressure on Brady is going to be key. The Ravens did a great job of it last week, but they couldn't seal the deal. They are also going to do everything they can to run up the middle.
If Seattle wins the matchup of Chancellor v. Gronkowski, that should cause the cards to tumble everywhere else.
Also, the Patriots are an all around solid football team by DVOA, but they aren't top 5 in any season category. (Top 5 offense in weighted DVOA, however.)
So, it'll be interesting. They are good enough to take advantage of Seattle mistakes, but Seattle should be favored for a reason.