Michelle, this is a good question and one long overdue.
I'd just like to say that my perspective is probably a little more international than most (having lived on three different continents and visted about 25 countries), and having seen a little more of the world, I can confidently say that there are very few places that are more screwed up with regards to sex in relationships than America in particular and English-speaking countries in general. (I haven't been to the Middle East, but from what I hear they're probably more screwed up than we are.) Look, sex is a natural biological function. A woman who doesn't feel ready to have sex shouldn't - but that "woman" is in some way not truly an adult as far as I'm concerned. Same way, a guy who worries about how many people his girlfriend has slept with in the past needs to get a different hobby. Sleeping with a lot of people doesn't mean anything other than - you've slept with a lot of people. Woopie.
To answer the original question, no, I wouldn't, as a policy, go out long-term with someone who I wasn't sleeping with any more than I would go out with someone who slept with me but wouldn't, I don't know, talk to me or something. As has been pointed out above, sex is a large and integral part of any adult relationship. If it's not there, then something's missing.
To look at it another way, I could go out with (a) a woman who's smart, funny, great looking, etc. but who won't sleep with me, or I could go out with (b) a woman who's smart, funny, great looking, etc. and will sleep with me. All of a sudden, it seems like a no-brainer, huh?