I'll hold my hope until I hear the sentence. Something tells me it will be somewhat lighter than community service.
Our judicial system in the United Methodist church is much like the US government's. My sense about punishment is that it will be moderate. First, the guy admitted to the gay marriage ceremony. Second, it is apparently his first offense (that's known). Third, his record to date has been positive.
Stacked against that is that he doesn't appear to be at all remorseful.
I will bet on a one or two year suspension from the pulpit along with a requirement for reflection, counseling, and study.
JMHO.