Credit Default Swaps -- "So What?" You Ask...

Here's a pretty decent primer about Credit Default Swaps:

http://www.moneymorning.com/2008/04/02/credit-default-swaps-a-50-trillion-problem/

If the premise is true, then I'm not sure I fully understand the argument that there is always a winner and a loser in a CDS transaction and thus no net gain or loss of wealth.