If Dylan is Nikki's child (which I believe he is) that wouldn't make him a Newman. It would make him Nikki's son, but not Victor's. The child is half sibling to both Nick and Victoria, but no blood relation to Adam or Abby.
I have to wonder what it will mean for Nicholas. If Nikki gets a brand new boy to mother and Victor is consumed by Adam, where does that leave Nick? I have a feeling the idea is to pit brother against brother over Avery, and I'm sorry I can't think of anything that would be more boring than a Nick/Avery/Dylan triangle.
I wish SB would just go back to GH before he eats this show alive the way he did in Port Charles.