The federal government, throughout our history, has deferred to state-law policy decisions with respect to domestic relations.Now count: how many states do we have? Fifty. How many states consider a same-sex marriage legal? Twelve (thirteen once the appellate court stay is lifted in California). How many states actively ban same-sex marriage in some way? I counted thirty-three on the Wikipedia list, but your count may vary by 1 or 2; and a lot of these (I didn't count) don't even allow domestic partnerships. Plus 5 states with no opinion. Just take a look at the map in the Wikipedia article:
Same-sex marriage status in the United States by state
Come on, people. This is good news for the federal benefits etc. of the residents of the few states that allow same-sex marriage. If you live, however, anywhere in the South, or on the Great Plains, or anywhere except California, Washington, and the New England states, your gay marriage is toast unless you can convince your local legislators to rule otherwise. Best of British luck on that.
Because the flip side of a decision that the states can decide about same-sex marriage is that any Congressional action to approve it nationally (assuming you could get such a thing through the current House, which is crazy thinking) would also be unconstitutional, because it's a states' rights issue.
Keep raising money for the campaign, folks. You still have a long row to hoe.