Utah Marriages will be federally recognized

Even if Utah won't recognize them, the Fed will (considering that they were legally entered into at the time).  From Equality on Trial quoting Atty General Eric Holder:

In the meantime, I am confirming today that, for purposes of federal law, these marriages will be recognized as lawful and considered eligible for all relevant federal benefits on the same terms as other same-sex marriages. These families should not be asked to endure uncertainty regarding their status as the litigation unfolds,” Holder says. 

In the coming weeks, Holder pledges to coordinate with other branches of the federal government to ensure federal benefits are flowing to same-sex couples who wed in Utah.