This is why Bush winning re-election in 2004 is such a monumental tragedy for progressives. Instead of a solid 6-4 liberal majority, the progressives are down 5-4 thanks to the John Roberts and Samuel Alito appointments. The only hope is the so called "swing vote" in Anthony Stevens. The problem is that he's not really a moderate in the mold of Sandra Day O'Conner. He has only occasionally sided with the liberal wing (hell he led the opposition to Obamacare).
Maybe the libertarian instincts in Scalia/Thomas/Alito will kick in. All the progressives need is for one of them to vote with the liberal wing and the gay rights movement can take a giant leap forward.