First off, for those of your that don't already know: the Ontario Court of Appeals has ruled that preventing homosexuals from engaging in marriage is contrary to the Charter of Rights and Freedoms.
From cbc.ca:
According to the Divisional Court, the federal definition of
marriage as a lawful and voluntary union between "one man and
one woman" violated the Canadian Charter of Rights and Freedoms.
Ottawa appealed the ruling, arguing marriage is based on a universal
concept of a union between one man and one woman.