Basically, issues of co-dependency aside, I think it's safe to say that we're living much more like a married couple already than most engaged people have throughout the vast majority of history. And possibly some married couples too — hey, I'm not here to judge.
Personally, I think this situation is awesome. I can go into my wedding day absolutely sure that this is a man that I'm not only head over heels for, but also a man that I can share a bathroom with without wanting to stab him. These things matter when you're 75, wearing dentures, and contemplating the slow but inevitable decline into wearing nothing but muumuus. (I plan to be as eccentric as possible in my elderly years.)
So it's been interesting to find out how many people think that living together pre-marriage seems to somehow make it “less special.”
The first indication I had was when my future husband looked at me whilst in post-coital bliss. “Should we, like, not have sex for two weeks before the wedding? You know, to make the wedding night special?”
Now, if self-denial turns you on then I'm all for this plan leading to stupid-hot sex, but I'm kind of a “more-is-more” girl myself. So I thought, if anything, we should be practicing pre-wedding — you know, to make sure we get it right.

Oh lord. The internet has its panties in a wad with yet another OMG SHOCKING!! wedding trend. This time it's "Morning after" photos, where a... Read more
He seemed relieved with my answer, but it didn't stop there. Since then my Mom has suggested that we “maybe hold off on some things to make it special,” (ew, Mooooooooom!) and I've read repeatedly about couples who even forgo kissing in order to make that First Kiss extra-special.
There's that word again. “Special.”
What's so un-special about the deep love we have? The commitment we're entering into? The fact that we know each other so well and are so happy to be spending the rest of our lives together?
Damnit, my wedding is going to be special because it's MINE. My whole marriage is going to be special, even on the boring days when we have to do our taxes, or the bad days when we get in a fight over what kind of milk to buy. For that matter, every time we have sex it's special, because it's us and it's an expression of love and because it's REALLY HOT. I don't need a wedding night to be turned on.
I don't believe you have to recreate some sort of pseudo-temporary virgin-hood in order for your wedding to be Special. I'm glad we're entering into this adventure with the knowledge and experience we have, and I wouldn't have it any other way.