Here's something from PFT (per Gantt) on the cap consequences of trading DeAngelo from back in November:
As Gantt pointed out on Wednesday, the Panthers areprepared to take the cap hit that would result from a trade of running back DeAngelo Williams. It’s important to clarify what the cap hit would be, and when it would apply.
Some (including me) believed as a knee-jerk matter that the remaining allocation of the $16 million signing bonus Williams received in 2011 would hit the cap now. Prior to 2006, that would have been the case — and that’s one of the reasons for a lack of trades of veteran players.
In 2006, the NFL and the NFL Players Association tweaked the labor deal to allow trades made after June 1 to be treated like cuts of players after June 1. In those situations, the team absorbs the acceleration for the current cap year and the balance of the acceleration in the next cap year.
For Williams, the $3.2 million bonus allocation would continue to apply this year. For a post-June 1 trade, the remaining $9.6 million would apply not this year but next year.
The cap charge would be offset by avoiding Williams’ $4.75 million base salary next season, which means that the Panthers would carry a net hit of $4.85 million in 2013, if they trade Williams before the 2012 trade deadline.
And while that’s not a huge amount, keep in mind that the NFL expects the salary cap for 2013 to remain flat. So it’s not as if the dead money will be subsumed within the normal annual increases in the spending limit.