Initial reading of the decision from the New Jersey Supreme Court (Lewis v. Harris [A-68-05]), it appears that the NJ legislature has 180 days to amend the marriage statutes to provide the option for same-sex marriages.
Update: Having read the majority opinion, here are a few extracts worthy of repeating.
“Although we cannot find that a fundamental right to same-sex marriage exists in this State, the unequal dispensation of rights and benefits to committed same-sex partners can no longer be tolerated under our State Constitution. With this Stateâ€™s legislative and judicial commitment to eradicating sexual orientation discrimination as our backdrop, we now hold that denying rights and benefits to committed same-sex couples that are statutorily given to their heterosexual counterparts violates the equal protection guarantee of Article I, Paragraph 1 [of the New Jersey Constitution]. To comply with this constitutional mandate, the Legislature must either amend the marriage statutes to include same-sex couples or create a parallel statutory structure, which will provide for, on equal terms, the rights and benefits enjoyed and burdens and obligations borne by married couples. We will not presume that a separate statutory scheme, which uses a title other than marriage, contravenes equal protection principles, so long as the rights and benefits of civil marriage are made equally available to same-sex couples. The name to be given to the statutory scheme that provides full rights and benefits to same-sex couples, whether marriage or some other term, is a matter left to the democratic process.” (pp.6-7)