I don't believe in "the one." The probability of, in this vast world with billions of people, finding the one person whom you were "meant to be with" in the standard person's lifetime, is just too small. It's a very negative standpoint, but it's true. XD There are so many people, it's a far cry to think that you'll find the person bound to you by fate when you're like...15-25. =\
That said, while I don't believe in any philosophy regarding one person being a soulmate, I do think that it's very possible for people to find people they feel so comfortable with that they could easily spend the rest of their life with him/her. I wouldn't call it a soulmate or "the one," because I believe there would be many, many other people with whom you could have the same effect, but...it makes a lot more sense than just one person.
Anyway, I think it wouldn't be much of a surprise that I'm answering this with a no. XD