For what it's worth, I would like to see the concept of civil marriage being both extended (to cover same-sex couples) and restricted (to be confined to the legalities), then any bolt-on stuff that the couple wished to throw in to reflect anything they wanted to say about love and commitment and so forth could be organised by them as an add-on with no legal significance (could be a church service, a humanist ceremony, having friends make a few speeches down the pub) if they wanted, or could be omitted entirely if they didn't want to make any public statement about their relationship. That just seems simpler to me -- I don't see the need to complicate things by having two parallel systems offering exactly the same legal rights just because (and I know I'm oversimplifying here) some people like the term "married" while others dislike it. Stick in some legal gubbins about how the legal relationship may be referred to as either a partnership or a marriage and let people call themselves what they want.
We got married... hmm... primarily for legal issues of one sort or another, probably with a side order of wanting to try to prove that it was possible to have a marriage that worked out and possibly a sprinkle of the fact that it wasn't really the done thing among our circle of friends so it was a bit rebellious. But the legal and financial issues were definitely the biggest element. And we did have a reception/party, because it was a good excuse and we hadn't thrown a really big party yet, and it was fun. We'll probably throw another big party when we turn 40, but I don't think that represents an unrealistic fairytale view of entering one's fifth decade.
I do find it odd that in many other areas advice would be not to worry about social attitudes or what people think, but that when it comes to marriage it seems to be a case of (crudely put) "Oh no, we couldn't get married. What would people think?". Is there an element that it's OK not to worry what people think if what they are likely to think is that you're a bit of an individualist, bucking the trend, ploughing your own furrow, etc., etc., but that suddenly what they think becomes really important if what they are likely to think is that you're a bit of a conservative, buy into a traditional set of moral values, have particular assumptions about gender roles, etc.? Just thinking aloud there, I suppose... I'm a bit surprised by how concerned some posters here, who I'd not previously thought were the type to worry about what other people thought, are about what assumptions might be made about them if they got married.