Marriage by another name?

The Civil Unions Act 2012 (ACT) is intended to enable couples who are unable to marry under the Marriage Act 1961 (Cth) to "enter into a legally recognised relationship and ensures that even though a civil union is different to a marriage it is to be treated for all purposes under territory law in the same way as marriage".

The Act repeals 

the Civil Partnerships Act 2008 (ACT) and amends the following statutes -

• Administration & Probate Act 1929 (ACT)
• Adoption Act 1993 (ACT)
• Births, Deaths & Marriages Registration Act 1997 (ACT)
• Civil Law (Wrongs) Act 2002 (ACT)
• Corrections Management Act 2007 (ACT)
• Crimes Act 1900 (ACT)
• Discrimination Act 1991 (ACT)
• Domestic Relationships Act 1994 (ACT)
• Domestic Violence & Protection Orders Act 2008 (ACT)
• Duties Act 1999 (ACT)
• Evidence (Miscellaneous Provisions) Act 1991 (ACT)
• Family Provision Act 1969 (ACT)
• First Home Owner Grant Act 2000 (ACT)
• Guardianship & Management Of Property Act 1991 (ACT)
• Instruments Act 1933 (ACT)
• Land Titles Act 1925 (ACT)
• Legislation Act 2001 (ACT)
• Married Persons Property Act 1986 (ACT)
• Parentage Act 2004 (ACT)
• Powers of Attorney Act 2006 (ACT)
• Rates Act 2004 (ACT)
• Sale of Motor Vehicles Act 1977 (ACT)
• Testamentary Guardianship Act 1984 (ACT)
• Wills Act 1968 (ACT)
• Witness Protection Act 1996 (ACT)

and the Births, Deaths And Marriages Registration Regulation 1998 (ACT) and Adoption Regulation 1993 (ACT).

Why bother? 'Modern Marriage and Judgmental Liberalism: A Reply to George, Girgis, and Anderson' by Matthew Clemente in Journal of Law and Social Deviance (2012) 1-66 comments that

State by state, cantankerous debates about same-sex marriage continue to capture headlines. The outcome of these debates has not only changed the political landscape in United States but has also impacted public policy and legal theory. Moreover, the same-sex marriage debate raises a more fundamental philosophical question — why is the state involved in marriage in the first place? I argue that the best answer to this question is that marriage plays a vital role in modern Western democracies, habituating the character traits that are essential to effective democratic citizenship.

The standard liberal justification of same-sex marriage is fundamentally flawed since it is precluded from discussing the “good” of marriage. In their article “What is Marriage?”, Robert George, Sherif Girgis, and Ryan Anderson exploit this weakness. After demonstrating the inconsistencies of the standard liberal justification, George, Girgis, and Anderson offer their own conception of marriage which inherently precludes same-sex couples. After examining their argument against gay marriage, I argue that it is rooted in an untenable notion of what is essential to marriage. By utilizing judgmental liberalism, a slight alteration of neutral liberalism, I answer George, Girgis, and Anderson’s objections to same-sex marriage. The state ought to encourage same-sex marriage because marriage, at its core, is about fostering fidelity, monogamy, and lasting stable relationships. Because this social function applies equally to homosexual and heterosexual couples alike, gay marriage ought to be permitted and promoted.