Here are the remaining play off teams and their D ranking.

SF - 3
Denver - 2
Seattle - 4
Houston - 7
GB - 11
Balt - 17
Atl - 24
NE - 25

As we have discussed, D ranked on yards allowed is not the total picture. I think points allowed is probably the more accurate picture. PPG looks like this.

Seattle - 1
SF - 2
Denver - 4
Atl - 5
NE - 9
Houston - 9 (tied)
NE - 11
Balt - 12

Looking at this list, defense DOES matter. The worst D is Balt. who is still in the upper half of D in the entire league, plus, they are likely to lose next week, meaning the team with the lowest D will not advance. And NE, being just 9th in points per game, have an offense that is insanely wicked, so they can survive a less-than-top rung D. Looking at this, D still matters greatly. Passing offense matters more than ever, but it still does not dominate in terms of making or breaking teams - D does. It's a chain link fence (every team component impacts the over all team) but D is still very critical.