It's apparently been filed by David Boies and, interestingly, Bush SG Ted Olson:

"For a long time I've personally felt that we are doing a grave injustice for people throughout this country by denying equality to gay and lesbian individuals," Olson said in an interview with The Advocate. "The individuals that we represent and will be representing in this case feel they're being denied their rights. And they're entitled to have a court vindicate those rights."

When pressed about his service with the Bush administration, which in 2004 endorsed an amendment to the U.S. constitution that would prohibit same-sex marriage, Olson said he was personally against the amendment at the time, though he made no public statements on the matter.

As for the timing of the suit, Olson said that recent decisions by the U.S. Supreme Court "make it clear that individuals are entitled to be treated equally under the Constitution. I'm reasonably confident that this is the right time for these [injustices] to be vindicated."

I doubt Olson is right about the timing, but no doubt this ups the ante on any future Supreme Court vacancies for Obama. (There's already a challenge to the federal DOMA in the First Circuit.)

(HT: Chris Geidner.)