The oft-injured core of the Panthers defense did not get any better in the offseason. You cannot continue to roll out the same guys and expect them to stay healthy. Dan Morgan and Kris Jenkins are very talented, but the injuries add up, and both have had more than their fair share of health problems. Also, Ken Lucas is not an elite corner no matter how many times Sean Saulsbery (that is spelled incorrectly on purpose) says so.
Keyshawn Johnson is not a savior. It is true that he's better than the sacks of shit that they lined up on the other side of Steve Smith...but the real point is that, at best, Keyshawn gives Carolina a second-tier offensive weapon. Beyond Smith, the Carolina's offense is pedestrian at best.
As for the rest of the NFC's contenders:
Dallas - T.O., enough said.
Washington - Who is the QB?
Chicago - Show me some offense.
NY Giants - No glaring weakness or great strength.
Philly, Tampa, Atlanta - Just not ready for prime time.