There have been some major developments in marriage equality over the last few weeks.  In addition to state legislatures in New Hampshire and Maine passing marriage equality bills, there have been developments in regards to Prop. 8 and the so-called "Defense" of Marriage Act (DOMA).  A gay couple from California who married while marriage equality was legal have filed suit against the federal government claiming that DOMA violates equal protection.  In response, lawyers at the Department of Justice wrote a brief defending DOMA and argue that it is constitutional.  To many this violates a campaign promise by the Obama Administration to rescind DOMA.  In contrast, the California Attorney General, Jerry Brown, has written a brief in support of the Perry v. Schwarzenegger case which argues that Prop. 8 violates federal equal protection.  In the brief, Jerry Brown invokes the Loving v. Virginia case and argues that DOMA does indeed violate the federal constitution's guarantee of equal protection.

Perry v. Schwarzenegger (complaint) -- Equal Rights Foundation

Jerry Brown brief in support of Perry -- LawDork

Smelt v. United States (case challenging DOMA, government's brief) -- ScribD

Update: The Human Rights Campaign, the country's largest LGBT civil rights organization, has responded to the DOJ's brief with a letter here.