I know both sides haven't really come close to a final agreement, but there actually has been some progress in these NBA negotiations. Among the new elements of this deal are an amnesty clause, and a new "stretch" exception.
There will be a one-time “amnesty” provision that will allow each team to waive a player (with pay) without his salary counting against the salary cap.
There will be a “stretch” exception, available every year, allowing teams to waive players and stretch out their remaining salary over a number of seasons, thus reducing the annual salary-cap hit.
I touched on the amnesty thing a bit when I railed against Bill Simmons last month. The Celtics just don't have enough players on the roster to start cutting people, amnesty or not. I'm also pretty sure a provision of the amnesty clause will be the inability to re-sign your own player.
So I don't think the Celtics can cut Paul Pierce, pay him all the money he is due to get him off the books, and then ...