It appears that Judge Kennedy is the key figure in deciding the legality of Gay Marriages. The court may decide that Proposition 8 should not have been heard in the Supreme Court. By doing so, the gay proponents would win by default since the California Court favored gay marriage for the state. If effect, the Supreme Court will use administrative maneuvering instead of deciding on the substance of the case.
http://news.yahoo.com/blogs/ticket/kennedy-decide-gay-marriage-cases-201558362--election.html