Have crawled from my sick-bed for just long enough for this post.
First, the bad news, Obama's DoJ are kind of dicks regarding the Defence Of Marriage Act. You can tell their dicks because their argument relies on not recognising a gay marriage is equivalent to not recognising a marriage between a man and a child. This is a rather more developed version of Bill O'Reilly's constant insistence that allowing two men to wed would open up the possibility of unholy unions twixt man and duck). It deliberately conflates a situation in which two people are clearly consenting adults but there is a question as to whether their gender allows for marriage with a situation in which two people are clearly of opposite gender, but there is a question as to whether both are consenting adults. Bonus dick marks can be added for once again arguing that DOMA does not discriminate against homosexuals because it also states non-married heterosexual couples don't get marriage benefits either (the relevance of Anatole French's observation that "[t]he law, in its majestic equality, forbids rich and poor alike to sleep under bridges, to beg in the streets, and to steal their bread" should be obvious here).
Here's the good news, though; I don't think DOMA matters, long term. Thanks to this handy graph, shamelessly stolen from Andrew Gelman via Kevin Drum, it looks like support for same-sex marriage is increasing across the board. It's only a matter of time (and not necessarily very much time, either) before the States hits critical mass, and it will be game over for the bigots.