While (at least for now) it is possible for same-sex as well as different-sex couples to legally marry, many couples choose to remain unmarried. If you are in a committed relationship without the automatic legal protections of marriage, you should think about using estate planning to protect your family. Legal marriage does not eliminate the need for estate planning, but the law makes assumptions about married couples and provides certain default protections that are not available to unmarried couples.
If your spouse dies, the law assumes that your spouse intended to benefit you with at least part of your estate (depending on whether your spouse has children). If you are not married, there is no automatic right to any property that is not already in your name. If you are not married, the only way to ensure that your partner receives any property is to make provisions in a will or trust that direct assets to your partner.