An AP article on CNN.com considers the question.
No point ($) in going after the original accuser. So you’re left with Durham County District Attorney Mike Nifong (and presumably the State of North Carolina), and perhaps Duke University?
Nilfong is very deserving, but possibly immune. Several pundits sound off on this issue in the AP piece. Duke may’ve created some liability for itself through its sanctions against the students prior to … anything legitimate. Innocent ’til proven guilty anyone?
Slander, libel and various flavors of wrongful prosecution come to mind as causes of action… doubtless there are others.
Should the players sue? These guys will be dogged by and tagged with this allegation for the rest of their lives – or at least for the foreseeable future. Their lives will be more complicated, and more difficult because of it. If they can recover damages to soften the hardships they’ll endure over this nonsense, more power to them.