The Myers-Briggs® instrument is a great tool for developing your relationship, learning more about your partner, and yourself. Here are a few things to keep in mind:
The Myers-Briggs test is NOT a good way to choose a partner. For those of you who look for partners by astrological signs, you will be tempted to do the same with the MBTI®. While you will learn a great deal about your partner, it's not enough to tell you if you will be soul mates or lifelong lovers. People are far too complex for a simple inventory to make those kinds of decisions for you. Fall in love first, then worry about type much later, when you are in a committed relationship. You can get along with any type and can have trouble with any type.
According to the Tiegers in their book "Just Your Type," the break down for couples is the following: all four scales the same: 10%. Three scales the same: 20%. Two scales the same: 35%. One scale the same: 25%. No scales the same: 10%. As you can see from these statistics, there's no real pattern. Any combination can work or break apart. If you check among your friends and family, you'll likely find all five combinations quite quickly.
My wife and I agree that knowing psychological type has helped us appreciate one another a great deal over the years. We are mirror opposites, so there's plenty of room for misunderstandings. I can say the same about appreciating my parents and siblings. Many things I used to let bother me now seem silly in light of this knowledge. It explains the way people make decisions and take in information. My wife often thought I did things just to aggravate her. As she learned more about type, her eyes were opened. The same thing happened to me. Type helps explain those little things that drive you nuts.
The kind of couple matters little. You can be gay or straight, roommates, or living with your parents, siblings, or relatives. Knowing about psychological type will make it easier for you to understand others. This knowledge will make all your interactions less stressful. As the title of one popular type book states, "I'm not crazy, I'm just not you."
If you're about to get divorced, I'm not sure this is the tool for you. I'd recommend going to an experienced marriage counselor. Sure, knowing your spouse's type might help, but you likely have other issues to resolve. Get professional help.