I'm rooting for Michael to get custody so Drew and Willow can begin to implode. She will begin to see Drew for who she really is, and realize what it's cost her to be with him. It would be poetic justice for Sasha and the baby to move into the gatehouse and build a big, happy family with Michael. Willow can only look through the window and wish she hadn't thrown it all away for a controlling jerk.
But seriously, it's rare that a custody case like this would be an either/or situation. Both parents are present in the kids' lives, neither is being accused of abuse or neglect, neither is a drug addict or alcoholic, both can financially provide for the kids and maintain safe homes. It would be more likely that the judge would grant joint custody. The kids would maintain access to both parents and neither would be allowed to move them away from Port Charles. That would be the more realistic outcome, but alas, soap world.