I actually agree with this guy.
Government should not be issuing "marriages" but "civil unions" with the same rights, advantages, and duties as a current marriage. Of course, such civil unions are totally secular and can include same-sex civil unions (that give the right to inherit from each other, and adopt together)
Of course, a church marriage should be totally irrelevant in the eyes of the law, and bestow none of the advantages of a civil union. It is, after all, a holy covenant between the couple and God. The state has nothing to do with it.
On the other hand, any church would be free to marry anyone they want, and to refuse marriage to anyone they want too.
I also advocate a transition period during wich any couple can present a marriage certificate and have a civil union certificate issued.
There. The sanctity of marriage is respected, and gays have the same legal rights as straights. Everybody wins.
P.S. In France, you have to marry twice - once at the church, and once at the town hall. The papers that matters are the ones signed at the town hall.