No, they do not. Marriage between same sex couple is still not allowed in the Temples nor can they be done by bishops of that sect. I am not sure of their stance regarding same sex LDS couple who marry via other religious ceremonies or civil ceremonies; but I know the LDS church does not condone or perform gay marriages anywhere.
The polygamy change was a completely different thing. It was possible for that change to be church-wide. The gay marriage issue would not be a church-wide thing, and no church allows something one place and not another, no matter what church it is.