This was also posted at Depressedfan along with some description. I think it's worth a read. Basically, the controversial "wins produced" stat was used in conjunction with player salaries in an attempt to determine which players are overpaid or underpaid based upon their contributions. It breaks down every player on every team. Scroll down and look at the sixers roster to see where the players ranked.
This by no means is the end all/be all to player value, but it's definitely worthy of stimulating some discussion.