Militancy aside, I reckon civil unions are the way to go. Marriage is a religious ceremony, and I believe it should be treated as such. We can't demand equal rights to a ceremony that involves an oath to a god in which we may not believe, any more than we can demand the right to a bar mitzvah. The whole problem of gay marriage is a problem of the separation of church and state that's never come up before: marriage is also a legal ceremony that provides a whole range of rights that we should, legally, also be allowed. So the solution is to separate the ceremony of marriage from these rights: let each church provide marriages in whatever way it sees fit; let the Catholics and the Anglicans sort out in their own time whether or not gays can get "married" by their definition. In the meantime, every couple, straight and gay, should be allowed to engage in a civil union, as a matter of human rights.
Undoubtedly, there are some Christians who believe that their creed allows them to marry members of the same sex. At the same time, there are some who believe their religion should let them marry several women at the same time. But these are religious matters, and should not be treated as such: a theological debate, disconnected from the cut-and-dried human rights case of civil union. We have for far too long given higher status to one religion's idea of what constitutes a union; it's time to break that tie.
"Marriage" is just a word. To us, gay marriage means an end to the denial of our rights. To others, it means an attack on their religion. And it is both, and if we are to get the rights we want then we must end their confusion about what we are trying to take away.