The US Navy has authorized its chaplains to perform same-sex marriages on military bases in states where same-sex marriages are legal. The chaplains are not required to perform the same-sex marriages, any more than they are required to perform any marriage ceremony.
You can see the official Navy memo, from April 13th authorizing chaplains to perform same-sex marriages. The central paragraph strikes me as reasonable, and equitable:
Consistent with the tenets of his or her religious organization, a chaplain may officiate a same-sex, civil marriage: if it is conducted in accordance with a state that permits same-sex marriage or union; and if that chaplain is, according to the applicable state and local laws, otherwise fully certified to officiate that state’s marriages...if the base is located in a state where same-sex marriage is legal, then base facilities may normally be used to celebrate the marriage. This is true for purely religious services (e.g., a chaplain blessing a union) or a traditional wedding (e.g., a chaplain both blessing and conducting the ceremony).
Mind, until the DADT policy is de-certified offiically and no longer in force, I doubt we'll see lots of service men and women lining up for military weddings. And since DOMA is still in force, the ceremony would be a religious ritual, without Federal sanctions. I do like the way it's made very clear that the chaplains may participate or not in a state authorized same-sex marriage ceremony based on the tenets of their faith, and their personal convictions.
Nontheless, be prepared for some hetero-normative chest-beating and public angst from conservatives of every stripe—this Navy Times article has some choice guaranteed-to-raise-your-blood-pressure quotes. I suspect in the next week we'll see lots of statements about the new policy being illegal, since Federal law via DOMA defines marriage as between a man and a woman. I also suspect we'll see some responses from less than careful readers who will assert that the Navy is forcing chaplains to perform same-sex marriages, even though the Navy is clearly and carefully establishing the rights of their chaplains to say "I prefer not to," as they can to any request to perform a marriage ceremony.
Still, it is a step in the right direction.