Hat tip: Extreme Skins.
Per Fox Sports (who originally broke the story):
For now the deal is dead, but that doesn't necessarily mean the deal is lost for good. It appears that the main sticking point is the fact that the Bears believe the pot isn't sweet enough as is.
If negotiations are to continue, both teams need to head back to the drawing board. The #31 plus Briggs for #6 isn't going down. The Bears want more, the Redskins don't want to give that up. Until additional formal offers pop up, I'm treating the Lance-Briggs-to-Washington-trade as MIA.