They can pretend that the Biden-eruption that presaged Obama's support for marriage equality was unplanned. But I for one am not buying it. Even before Biden's interview, I had noticed statements of support for marriage equality from higher and higher officials, closer and closer to the President. I had already begun to hope that a change in the official position was forthcoming.
The trial balloons exploded, and no one paid much attention. Afterall, the conservatives already hated Obama for supporting gay marriage, just like they hate him for trying to take their guns. So there was nothing stopping him from actually supporting equality.