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.
A copy of the decision is available here.
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 State’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)