I saw an article that says that he shows *attack dog potential* against John McCain.

On a conference call with reporters arranged by the Democratic National Committee (DNC), Edwards said that despite McCain’s well known military biography, voters should question whether they “really know” the Arizona senator’s history on veterans issues.
“All Americans respect Sen. McCain’s military service,” Edwards said, “but more would be surprised that Sen. McCain has consistently voted against increased funding for veterans healthcare and benefits.”

Edwards pointed to McCain’s opposition to Sen. Jim Webb’s (D-Va.) GI bill earlier this year as well as Obama’s higher legislative score from the Disabled American Veterans (DAV).

Here's a link to audio of that call.

He's mentioned also in this CNN article.