If it goes to an uncapped year, then there is also no salary floor. Meaning every team can spend exactly how much they want.
rookie contracts would extend a year, so for example, Jason Campbell would be an unrestricted FA this year with a cap, but if no cap is in place, then he becomes a restricted free agent.
teams will be given an extra franchise (transition) tag.
the top eight teams can only sign a FA at a 1:1 pace, meaning that if they sign a FA they have to let another player (i think equivalent contract) go.
Players will be able to moved without salary cap implications, meaning high paid players could be cut and no penalty would be assessed.
The intent was to make a capless year something neither side wanted to happen, so player movement is extremely restricted which affects the union, and obviously high salaries affect the owners.
They have until March 1st to sign a new agreement or the next year will be uncapped.
That is my best understanding of it.