Okay, I didn't know how searchable that last bit was, so I will consolidate.
I believe in civil gay unions, particularly if the same legal etc requirements cannot be done with a will or a medical directive or other legal instrument. I honestly do not believe one can see into the future enough to figure out what things marriage would cover, things which might require additional legal instruments. Would love to see more written on the topic.
Of course, I do not believe such can be legislated to be followed by any church, so they can do as they like.
I do not appreciate that, according to some arguments, the institution of marriage exists for procreation and it thusly defines marriage. I disagree, not for the homosexuals among us, but for the menopausal and infertile. This would imply that women over the age of 50 or so should not be allowed to marry. It would also imply that women with gyn diseases such as PCOS or endomentriosis should not be allowed to marry. (And what would happen if the diagnosis was made after marriage?) Further, it implies that guys who can't get it up or shoot blanks should not be able to marry.
So comment and enlighten as you wish.