The main problem for Seattle is going to be the same main problem New England had (IMHO): pass rush.
Manning had time to make sandwiches, send out some tweets, and read the daily paper back there. All day. His decision making is so quick and so precise, it's scary. I heard someone say (not sure if it's true) that Manning has yet to be even knocked down
in the playoffs so far.
I think Denver's defense is good enough, and Seattle's offense suspect enough, that I have a hard time seeing the Seahawks outscoring the Broncos.