For me there's a difference between a relationship where both partners have decided it's fine and dandy not to legally marry, and one where one partner dearly wants to marry but the other is very hostile to it.
My view on it (which sadly runs contrary to the way it seems to be resolved IRL) is that if it's just a piece of paper and meaningless to one person, then why not do it, given that it does mean so much to their partner? What harm could it do? Let's face it, if you have a house and kids together then any split will be messy as hell anyway. And I am never convinced by the 'so many marriages fail, what's the point?' arguments: if you only ever did things that were 100% guaranteed to succeed, then most of us would never be doing anything in life. We all commit to jobs all the time, knowing that they may not work out yet hoping that they will actually be jobs we want to stay in for a long time, even to the end of our (working) lives. Why not give marriage the same kind of chance?
I also think that the historical baggage of what people expect from a wedding is no reason to be put off. Show that you can get past that. Go down to the registry office by yourselves in your lunch hour, or go with just a few friends and have a curry afterwards - whatever it takes. There's no need to spend a fortune or feel you have to do all the trad stuff. Making the commitment is what's important, not who's there or what you wear.
I'm in the same position as kat2907 - married but didn't change my name, and planning to give my DC husband's name on arrival. Double barrelling is fine if you like it, but it's not for me. I will have given birth to DC so, while I accept I may get the occasional pang about us having different names, it's not the biggest thing, and it will be a good opportunity for me to teach DC that you don't judge people by their names (or having the same name), but what they are like inside. Plus I am fine with being called 'Mrs Husbandsname' informally when needsbe - I've always got that option, plus the legal protection of being married to DC's father - while that wasn't why we got married, it would always have been a factor for me in deciding to have a child with someone.