One of the interesting things about Julian Assange is that, love him or hate him; he's a guy who never seems to bluff. If he says something is coming, it usually does. The world may pounce on it, or choose to ignore it, but he almost always follows through on his threats/promises.
So, if you're Hillary Clinton, his recent ITV interview must be unnerving. In it, Assange promises that Wikileaks has more of Hillary's emails ready to go, and that the new info would add to the already indictment-worthy mountain of incrimination.