I'll play.
The entire front line. In the 4-2-Nickel BB was using Burgess and TBC on the edge. Inside he rotated Warren/Wilfork with Green/Seymour. Wright or Pryor replace Seymour now that he's been traded. Pryor is unproven, but he sure demonstrated some explosion in preseason and got a lot of pressure on the QB. There's some pocket collapsing power there.
Another element of this Nickel package is Mayo's offseason development and his improved understanding of the defense. He demonstrated a new potential as a blitzer, his partner Adalius Thomas can do the same thing. Let's not forget Guyton contributed to at least two sacks last season pressuring the QB into another rusher as a blitzer from LB, he also recovered a fumble in mid-air, the kid can make some plays as a rusher. Finally we have Meriweather who had two sacks last season, Sanders who was a decent blitzer in college but hasn't been used that way as much with Rodney ahead of him in the blitzing line-up, and Pat Chung who can come in as a Nickel Safety and put on a good blitz too.
Where is the pressure coming from? All over, especially if the CBs can step up to the plate.
Meriweather and Sanders are a year smarter and were working together very well toward the end of last season - improved. Wilhite was starting toward the end of last season, he's done nothing to indicate a decline in preseason - improved over O'Neal and about the same from the end of 2008. Butler is the Nickelback, last season Wilhite was, it looks like an improvement on paper and from preseason. Bodden is the mystery, he looked pretty good in preseason, but until I see him play against Buffalo I can't say he's an upgrade over Hobbs, but I don't think he's a downgrade - we'll see.
Linebackers also factor into this. Mayo was getting better in coverage late in the season, I think he'll continue to improve as the season rolls on. Thomas is pretty good, having him available in Vrabel's old coverage role works for the Pats. Guyton got written up by Reiss for his coverage against Leon Washington in the loss to the Jesters last season, he shut Leon down - that's damned impressive. Woods and TBC have done a decent job when they've been called on in coverage. I've seen Burgess cover the RB into the flat and do a good job, so NE can switch things up a bit and still be effective.
I think the Linebackers will be the key, Mayo is no longer a rookie, neither is Guyton, that is going to make a huge difference, especially as the season works to get them smarter. The other area that will make a difference is the Safeties. Meriweather appeared to make some key mistakes last season as he took over for Rodney, I think those days are past, he's fully seasoned now. Bodden is a veteran, a larger CB more capable of being physical in a phone booth than Hobbs - I think he'll be at least a slight improvement over Hobbs in that regard. Finally, Springs is a veteran who will make a difference in short field situations - he's seen it all before and if healthy (the big if) he'll be able to diagnose plays and disrupt things before they occur.
The things I talked about for Third down apply here too. There is one upgrade in the goal-line package to note - Eric Alexander replaces Larry Izzo. Folks may not have noticed before, but Izzo was a goal-line regular, Alexander is bigger, stronger, better able to take on blockers, and I think an upgrade.
Hurt it? Not so much. Better? Not right away, but let's see how the youngsters develop as they get more experience playing in the time slots Sey would have filled. Change the way Dean Pees does business a bit, yes, that will occur. I think in the short term there will be growing pains as Pees works out who needs to do what to replace everything Sey brought to the table, but I think the overall talent on the DL is up to the task. And you can't argue that big Ron Brace doesn't create an imposing presence inside against the run.
Yet? Perhaps not, but Buffalo is a good tune-up.
If there is anything that has me concerned it's the CB depth chart. Once you get past the apparent starters, Bodden and Wilhite, and Butler as Nickelback, there are questions about Springs (health, age) and Wheatley (slow starter last year and more of the same this year). Chung's ability to help in coverage inside helps, as does Guyton and Mayo's development in the passing game.
I'm giving Wheatley the same benefit of the doubt I've learned to give Ben Watson - Watson, for whatever reason, always seemed to struggle as a blocker at the start of the season, but he got better as the season went on. Wheatley developed that way last season, to the point where he was even inactive for one game, but he was looking reasonable by midseason when he took over O'Neal's slot.
We may also see Mike Richardson back in NE colors later in the season if his hand heals enough and there is an opening after an injury, he's not that bad a CB.