So, the story is an old one, but as is often the case with stories like this, it takes time before the details come out, and the devil in this case is very much in the details.
From the New York Times: In U.S. report, brutal details of 2 Afghan inmates’ deaths. The Times is going to rotate the content behind their for-pay barrier at some point, so here are links to some webloggers with outraged reactions, and significant amounts of quoting from the article: Pulpified (Digby of Hullabaloo), and The death of Dilawar (Jeanne of Body and Soul).
You can support Bush’s “war on terror” or not, view the larger goals of our military action in Afghanistan as justifying this sort of thing or not. But regardless of what position you take on that, you have an obligation, I think, to include the specifics of what actually happened in this case in your cost-benefit analysis.