He'll be back, I'm sure. It's probably one of the typical EE slow burning storylines that will resurface every now and again.
They could do so much with this storyline - a child abusing his mother - but I just don't think the actor has the ability to portray it. Harsh, I know because he is so young, but he needs to be a real Jekyll and Hyde character so that the Mitchells, school etc don't believe that little Denny could be hurting his mother.
That's my opinion, anyway!