What happens when same sex couples split up and there is a custody or visitation dispute over the child born during the marriage? The New York courts are recognizing that children born to same sex couples have two parents. Even though one parent is not biologically related to the child, since NY recognizes same sex marriages and permits same sex marriages the non-biological parent has the same rights as the parent who carried the child.
The presumption of legitimacy of the child born during the marriage applies and so do the rights to parenting time and the obligation to support the child. Where both parties have signed the birth certificate the realities of artificial insemination will not bar the rights of the spouse.
In my opinion, the decision is correct and is the natural consequence of permitting and recognizing the rights of same sex couples to marry and divorce. If they can have health insurance as a family and can inherit from each other as a spouse then they certainly can parent together.