Redefinition of marriage is not a human right, sorry. I can't decide I'd like to marry my work and have society accept that as marriage. Marriage has a definition, that up until now hasn't included gay couples. Changing that is not trivial, is not a law of nature and is not supportable on human rights grounds.
Let's, for the sake of argument, assume that gay couples are already free to live together and enjoy the protection given to married couples: inheritance, hospital/prison visiting rights, IRS deductions, [whatever social right I may be missing]. I know that is not the case; bear with me.
Now, imagine that a group wants to reserve the right to call marriage limited to a long term commitment between man and woman. Also imagine that gay couples want to call their long term commitment a marriage.
Now, you have an unsolvable problem. Both groups may argue that it is their right to define what marriage is all the way to the end of times. The problem is mostly with the naming of the concept; it is not with rights attributed to gay couples. Framing the discussion around the concept is actually hurting LGBTQ movements.
My personal opinion? Grant all, and I mean all rights to gay couples that classic couples have. Use the first-come-first-served rule and maintain the term marriage to mean a classic family. Create a new term for gay couples.
Give it two generations and this whole shout war will subside, and by then everyone will naturally call gay couples married couples, just like any other. In the mean time, important goals can be reached faster (like visiting rights).
Straight folks just want an exclusive right to define it, and on that basis deny that right to other people. Well, sorry, but nobody ought to have that exclusive right, especially when it's little more than a fig leaf to deny privileges to a group of people. We all know the real reason. It's religious, which just doesn't hold any water, and everybody knows that.
And your remedy is "separate but equal." Non-starter.
> "Gay couples have been allowed since 2005 to enter "civil partnerships", conferring the same legal rights as marriage, but campaigners say the distinction gives the impression that society considers gay relationships inferior."
Discrimination exists, and this same "different name" concept has existed, with socially damaging results, in the past:
What has been the symbolism of marriage in our culture? Part of it is definitely gender-neutral: celebration of a couple's love and their commitment to each other. But it has also been about the particular dynamic and beauty of a relationship between a man and a woman, including procreation. This part is very important to many people and it is taken away if the custom of marriage is changed to include gay couples.
I think this is a legitimate cultural dilemma where both sides can be empathized with. Opposing gay marriage (but not legally equivalent civil unions) can be a legitimate position that doesn't necessarily imply any sort of intolerance or hostility towards gays. Moreover, it is intolerant not to respect this position. I find it unacceptable for people to be ostracized and disenfranchised just for wanting to preserve a custom which they hold dear and which is part of their cultural identity.
You may think it's all just academic, but I'm actually convinced that a significant proportion (though probably not the majority) of gay marriage opponents isn't anti-gay. The unnecessary polarization of the debate doesn't serve good to the gay community either, as they feel more threatened than they should - such as in the case of Brendan Eich becoming Mozilla's CEO.
As for me, I think marriage shouldn't to be sanctioned by the state any more. Civil unions for everybody and let the cultural stuff be figured out organically.
Marriage is tweaked when needed.
Oh wait, they did: http://en.wikipedia.org/wiki/Separate_but_equal