Falcons have a much more dynamic offense. Julio Jones and Roddy White are two number one wide receivers. Tony Gonzalez is one of the best tight ends to ever play, and still has some gas in the tank. Michael Turner hasn't gotten much use this year, but he's still one of the better running backs in the league. Matt Ryan is having arguably his best year yet. They also have a pretty solid defense.
The Seahawks have one of the best defenses in the league. Their secondary is huge and hits hard. Russell Wilson keeps plays alive with his legs and is always a threat to run. Marshawn Lynch is a beast. Wide receivers are nothing special though, and the offensive line struggled at times tonight (though its been solid). Injury to their D-lineman (forget the name) who leads the team in sacks could be a huge loss if he doesn't play next week.
On paper its a real good match-up. I'm a huge Russell Wilson fan, but I think the Falcons squeak by. Atlanta is a VERY good home team, while Seattle is known to struggle at times on the road. Falcons also are trying to get that monkey off their back and get that playoff win they've been unable to get for the past few years, so they'll be playing with a chip on their shoulder.