The returning NT was in the news twice last year - Carolina signed him for 3 years, and then once able to return from the lockout, he immediately tore a triceps muscle and was sidelined for the year. So, consequently, little is known about him from the average fan's perspective - they know he was supposed to start, and will start, at nose tackle. Most know he's older (33 now). That's about it.
The 2001 3rd round pick by Buffalo came from Texas A&M, where he started 35 consecutive games at nose tackle. Coming out, he was a 290 lb under tackle, having run a 4.83 40 at combine; he had a solid first step and good strength, but didn't make a signficant amount of impact.
He was with Buffalo for five years (two as a starter) before going to Kansas City and starting there five years. Somewhat miscast in the 3-4, Edwards struggled in 2009, but finished strong in 2010.
Now at 325, he's aiming harder at being hard to move. At NT, he's gotta be willing to take on a double team. But, he's still being asked to play a gap, don't forget. If two guys are in that gap, he's gotta stay his ground, but it's safe to say that hole is covered now. He's not controlling the center, and playing off both sides of him like a two-gap NT would. Carolina's 100% one gap, remember.
So Edwards, who is expected to play mostly at NT, will occupy the middle of the defense, hopefully for around 600 plays. He'll be the guy in front of, and between, Jon Beason and Luke Kuechly. That trio will be determined to control the A and B gaps. Consider this:
So, in a passing league does a quality interior run defense mean anything anymore? Well, the Top 3 A-Gap run defenses and the Top 4 B-Gap run defenses all went to the playoffs. The playoffs, in the end, showed that even with the proliferation of the passing game, this league is still about balance and stopping inside runs is still a part of that. Not stopping the inside run to the extent that it harms the rest of your defense by overcompensating is, in itself, alarming. The best defenses–the likes of Baltimore, Pittsburgh, San Francisco, and Houston at the top of these lists–controlled the heart of their defense without having to draw players inside or blitz the inside gaps so frequently that it hurt them elsewhere.