I was watching this talkshow on tv. The topic was about soulmates & I've learned based on seeing that episode that you might not necessarily end-up with your soulmate in your current lifetime but possibly in your next. The reason being is that you're probably still in the process of paying your karmic (karma) debt to the people in your life. They could be a family member, a friend, an enemy, or even your partner or spouse. This "payment" of karmic debt is a means of preparing you when the time comes that you finally meet your soulmate. Now it doesn't follow that life would be less meaningful if the person you have a long-term relationship with right now is not your soulmate. The reason behind this is that your partner may have something important to teach you. BUT you will eventually end-up with your soulmate. You don't even have to search for him/her. 
Here are some facts about soulmates: (1) Complete force of attraction: It means that even if you were living in Timbuktu & your soulmate is in New York, your paths will cross in certain places and times, and it will keep on crossing until the two of you get in full contact with each other.
It is as if there is a magnetic force pulling the two of you to come together. (2) Connection & attraction in all levels: physical, mental, sexual, spiritual, etc. If there are differences in tastes in music, fashion, food, etc. these are but minor details. What I'm referring to are deeper connections resulting in a sense of harmony in both parties. (3) Your relationship makes better people out of the two of you allowing each one to evolve into better human beings. (4) The two of you can't live without each other: You always miss him/her. You always think of him. You feel good thinking about him. You feel good when you are with him. The same goes with your partner, because that is what soulmates are...two souls joining together to become one complete being. Quite romantic when you think about it huh?