Head of the NFL Players Association DeMaurice Smith addressed the media for about 30 seconds, and basically gave an ultimatum to the owners. He said that "significant differences remain", and if the owners want to extend again, they must agree to turning over 10 years of all financial data, or else no extension, and the union will de-certify. The owners have until 5:00 pm ET to decide what they want to do.
The Union is clearly playing hardball with the Owners, as they feel they have an advantage over the Owners if they were de-certify. We'll continue to update this thread with any new details.
UPDATE (5:03 ET): Chris Mortenson of ESPN just said on Sportscenter that the NFLPA has filed for de-certification, so the NFLPA no longer represents NFL players, and we will now see how this plays out in a court room.