I just saw this question.
On one foot, I'd say premarital sex is a good thing, even in the frum community. This is, of course, only assuming both parties are being responsible about it, are willing participants and using condoms (at least).
Here's one reason. I just read about a young man who apparently committed suicide the day after he got married. The man had issues stemming from sexual abuse as a teenager. While it's not reported, I'd have to guess he couldn't touch her on their wedding night, which lead to all kinds of problems. Perhaps - maybe - had they engaged in some physical contact prior to the wedding, they would have been able to talk it out.