Whenever Dean is on screen, I consciously detach him from the rape story; it's the only way I can be interested in the character. He was - and should be - a young, viable male character for the show, but the rape story has tainted him. It clearly was a mistake to run the story and, you get the feeling TPTB know it, but won't admit it.
It's realistic for a rapist to go unpunished. But, I think for a soap, they really should wrap that story up in some way. Have him admit his guilt, and begin a redemption arc. It worked for Kane in Home and Away, who went on to become a popular character (possibly helped by his love story with Kirsty), and it could work for Dean, too, with decent writing.