I think a constitutional amendment will be passed in November and that none of this will be relevant.
You might want to read the Court's decision closely. Note the bolded below:
"As discussed below, upon review of the numerous California decisions that have examined the underlying bases and significance of the constitutional right to marry (and that illuminate why this right has been recognized as one of the basic, inalienable civil rights guaranteed to an individual by the California Constitution), we conclude that, under this stateís Constitution, the constitutionally based right to marry properly must be understood to encompass the core set of basic substantive legal rights and attributes traditionally associated with marriage that are so integral to an individualís liberty and personal autonomy that they may not be eliminated or abrogated by the Legislature or by the electorate through the statutory initiative process. These core substantive rights include, most fundamentally, the
opportunity of an individual to establish ó with the person with whom the individual has chosen to share his or her life ó an officially recognized and protected family possessing mutual rights and responsibilities and entitled to the same respect and dignity accorded a union traditionally designated as marriage. As past cases establish, the substantive right of two adults who share a loving relationship to join together to establish an officially recognized family of their own ó and, if the couple chooses, to raise children within that family ó constitutes a vitally important attribute of the fundamental interest in liberty and personal autonomy that the California Constitution secures to all persons for the benefit of both the individual and society.
Furthermore, in contrast to earlier times, our state now recognizes that an individualís capacity to establish a loving and long-term committed relationship with another person and responsibly to care for and raise children does not depend upon the individualís sexual orientation, and, more generally, that an individualís sexual orientation ó like a personís race or gender ó does not constitute a legitimate basis upon which to deny or withhold legal rights. We therefore conclude that in view of the substance and significance of the fundamental
constitutional right to form a family relationship, the California Constitution properly must be interpreted to guarantee this basic civil right to all Californians, whether gay or heterosexual, and to same-sex couples as well as to opposite-sex couples."
The court has stated that these rights cannot be "referendumed" away - in fact, it's clear that should voters attempt to do so, the California Supreme Court might determine that marriage, if it can be thus limited, is not an inherent Constitutional right and prohibit it for everyone.
Be careful what you wish for.
Two things wrong with this post:
1) As has already been briefly brought up, California has a three pronged system of popular democracy consisting of: a) the Legislative referendum, b) the statutory ballot initiative, and c) the initiative constitutional amendment. The court has stated that neither of the first two may override their ruling, but the latter is a constitutional amendment in full force and has all the power of such in this matter.
2) As for the second piece in bold, I just want to point out that this is not how rights work. If the Court were to rule that marriage itself is not a fundamental right, all that would do would be to give the legislature the discretion to regulate it. Marriage would not suddenly become a prohibited act.