The business with Ramsay Snow, Roose Bolton's bastard, and his obnoxious servant Reek, is really complicated and would have been a nightmare to do justice to on screen. In the book, Ramsay hardly appears, but he's talked about a lot — he kidnaps Lady Donella Hornwood, forces her to marry him, and then imprisons her. And when Ser Rodrik Cassel shows up to deal with him, he changes clothes with his servant Reek, so as to escape. Later, still pretending to be the servant Reek, Ramsay Snow joins up with Theon, and it's "Reek" who comes up with the plan to kill the miller's sons and pass them off as Bran and Rickon. Eventually, Theon sends "Reek" to get help, and Ramsay returns with a small army. He pretends to join forces with Ser Rodrik, then betrays him. And later, once he's rejoined Theon, he betrays Theon as well. It's a very complicated story that's mostly told second hand, and the notion of having a character we've never met in disguise as another character we've never met could have been impossible to portray on screen. Given that Ramsay is mentioned often but not seen in season two, there's no doubt we'll meet him in season three.