The vote was 4-3, with a majority opinion and three dissents. Howard Bashman has the links here. From the majority opinion:

  We conclude that, in light of the history of pernicious discrimination faced by gay men and lesbians, and because the institution of marriage carries with it a status and significance that the newly created classification of civil unions does not embody, the segregation of heterosexual and homosexual couples into separate institutions constitutes a cognizable harm. We also conclude that (1) our state scheme discriminates on the basis of sexual orientation, (2) for the same reasons that classifications predicated on gender are considered quasi-suspect for purposes of the equal protection provisions of the United States constitution, sexual orientation constitutes a quasi-suspect classification for purposes of the equal protection provisions of the state constitution, and, therefore, our statutes discriminating against gay persons are subject to heightened or intermediate judicial scrutiny, and (3) the state has failed to provide sufficient justification for excluding same sex couples from the institution of marriage.