So, if the Polish woman was released and there is no body for Margaret Hassan, what was the ID for the disembowelled body of the "blond" woman that had the arms and legs cut off?
As for the identity of the blonde woman, my guess would be that they've either got several hostages that they've never mentioned... or there are members of these terrorist groups who are "western" in appearance -- who can be left as decoys if and when they fall in battle. Or maybe a little of both.