Problem is, King Dunlap isn't the only bad left tackle playing in this game. As far as sacks allowed go, Falcons' Sam Baker has been the worst LT in the entire NFL. Baker has given up 5 sacks so far this season, which is the second most of any offensive lineman in the league and the most by a left tackle. Baker is facing Trent Cole, who is third in the NFL in sacks over the past 3 seasons.
You could certainly make the argument that this is just as big a mismatch as Dunlap vs Abraham and it's just as likely to be a major factor in who wins this game.
One more thing... You know how many sacks the much maligned Jason Peters has given up? One and a half. That's the fewest on the team amongst the guys who have been starting since week one. There's no denying that his penalties are an issue, but he's still dominant in the run game and has not been giving up sacks even while playing on a line that has allowed the 3rd most sacks in the NFL.