The UN option has never really been an option so this is the best hope for achieving pressure against Assad. It's not a great option but since invading Syria is even worse, it's about the only viable option. The Guardian:
Hillary Clinton has called for "friends of democratic Syria" to unite against President Bashar al-Assad following China and Russia's veto of a tougher UN response to his regime, which she described as a "travesty". Speaking in Sofia a day after the collapse of the UN security council resolution, the US secretary of state said the international community had a duty to halt ongoing bloodshed and promote a political transition that would see Assad step down. She said the "friends of Syria" should work together to promote those ends. Clinton was harshly critical of Saturday's veto by Russia and China that blocked UN action against the continuing violence in Syria. "What happened yesterday at the United Nations was a travesty," she said.