I think.....

Michelle will get pregnant, still unaware that Leanne's baby is Steves.

Peter and Leanne will reunite, with Peter happy to be Dad to her baby ,unaware who the father is.

Come Chirstmas, michelle will loose her baby.

Steve, after getting used to the idea of fatherhood again, will then decided he has to be involved in the life of his and leanne's child.

Cue all hell breaking loose for added festive cheer..