GLAD is representing plaintiffs challenging the DOMA (federal Defense of Marriage Act) in the federal district court in Boston, the case, Gill v. Office of Personnel Management. See here for a press conference (kind of hard to hear -- there is a lot of traffic and wind noise). The GLAD site has lots of info and documents. If you stick past the attorney from GLAD, you get to hear from the various plaintiffs, and it's really worthwhile. You begin to hear their stories and get a personal view of how the Defense of Marriage Act unfairly impacts them and their families.
There is a separate, but related lawsuit by Massachusetts Attorney General Martha Coakley challenging the constitutionality of the federal DOMA in federal court. Further, there is a bill, HR 3567, "The Respect for Marriage Act" which ... "Amends the Defense of Marriage Act to repeal provisions allowing states, territories, possessions of the United States, or Indian tribes to give no effect..." The last action on that bill was that it was referred to the Subcommittee on the Constitution, Civil Rights and Civil Liberties on October 19, 2009. I don't know if that means it is stuck and languishing, but it looks like it to me. Maybe it has to be introduced again each year.