One of the questions everyone is asking about the approval of a provisional rite for same-sex blessings is how it changes our understanding of marriage. It's a complex question, and I'll start with defining "Marriage" and "Matrimony. " These are often used interchangeably in both the culture and the church, but I'm going to define these just for use within this post.
"Marriage" is a civil affair binding two individuals together legally. This is the ancient definition of marriage which predates Christianity.
"Matrimony" is a sacrament, or sacramental rite, or has no religious status at all, depending on your time period and which strain of Christianity you belong to. It's important to note that matrimony can be seen as kind of a "Junior Sacrament" due to its relative newness.
Jesus spoke of the of the permanence of marriage, but not the moral goods. Paul saw marriage as a poor second to celibacy, as did most early Christians. Gregory of Nyssa (d. 385 or so) was one of the first to see a possibility of divine work within marriage equal to that of celibacy, in that it trained people in impermanence.
The role of the church in marriage only began to pick up when it became the established religion of the Roman Empire. As ministers became civil officials, they took on civil roles, including solemnizing marriages. The church slowly began to develop a sacramental theology of matrimony. By the early Middle Ages, marriages begin to be celebrated in churches. By the late Middle Ages, marriage and matrimony combined as the church took over many of the civil functions of the defunct empire and became the sole purveyor of marriages.
This is the confused understanding of marriage and matrimony that we inherit - one born of a confusion of religion and civil government. Clergy in the United States that perform marriages function simultaneously as religious and civil officials. It's important to note that the center group of one of our most cherished American myths, the puritans fleeing religious persecution, believed that marriage was a purely civil affair and rejected any sacramentality around it.
In the modern situation, we face our old confusion. While Europe has separated civil marriage from religious matrimony, The United States continues to conflate the two. This gets especially difficult as the civil authorities redefine (or one could say refuse to define in specific gender terms) what marriage is. In many states, same-sex marriage is legal, while in others same-gender unions are legal, while in others constitutional amendments make such civil recognition impossible.
It is into this morass that the Episcopal Church wades. There is a cultural expectation that when you celebrate the sacramental rite of matrimony in church, you are married in the eyes of the state. Our canons state that matrimony is between one man and one woman. So what exactly is happening in a same-sex blessing? Is it matrimony or not? Is it marriage or not?
The response of the church with a proposed rite allows us to address the varied situation in the United States. It seems to me that the rites are clearly NOT matrimony. For them to be so, we would have had to alter the canons. There are those that say, "if it looks like a duck and quacks like a duck, then it must be a duck." This line of reasoning points out that since there are vows and an exchange of rings, it looks too much like matrimony to be anything else. But this completely disregards a regular part of our religious life in the Episcopal Church, namely that of monastic vows. Those rites within the various religious orders of the Episcopal Church also have vows and sometimes include a ring but almost always include some token of the vows. While matrimonial language is sometimes employed metaphorically (I.e. "Bride of Christ") no one would claim that such vows are the sacramental rite of matrimony. Saying that liturgical similarity implies sacramental correspondence ignores this important part of our tradition. Saying that monastic rites are not sacramental just because they are not matrimony would be a rather startling assertion. The same could be said of same-sex blessing rites. Just because they don't fit the category of one of the sacramental rites does not mean they are not sacramental in nature.
What the rites definitely are is a recognition of a covenanted relationship between two people, of which there are many precedents in history. How they interact with marriage and matrimony will vary from place to place. In places where same-sex marriage is legal, it will mean that a clergy person will not be celebrating matrimony, but MAY be solemnizing a civil marriage. In places when same-sex marriage is not legal, a Clergy person will neither be celebrating matrimony, nor solemnizing a civil marriage, but simply blessing a covenanted relationship. In many places, the rites will not be used at all because the diocesan bishop will not authorize their use. This flexibility is necessary at this time, not only due to theological diversity, but due to legal issues with civil marriage in many states.
There may be those, both for and opposed, that will insist that this really IS matrimony. There could be truth in that, since matrimony is a sacramental rite in which the couple itself are the ministers. The priest only adds the Church's blessing to their sacramental action in the vows. Thus, it could be matrimony whether the church believes it or not. (Though technically, if the church does not recognize it, it may be sacramental, but it is not a sacramental rite.)
What the church will do in the future is unclear. We may move towards accepting same-sex rites as being matrimony by adapting the Prayer Book rite and changing the canons. Or the GLBT community may decide that what they are doing is something other than matrimony (A position I have heard articulated by several GLBT individuals.) In any case, the current rites provide something for a time in which we need to address various needs in multiple contexts.