It's not likely to happen, though. You can read the parties' filings here. The Petitioners' argument against Proposition 8 is worse than feeble. Their claim is based on the fact that California's Constitution distinguishes between "amendment" and "revision" of that document. An "amendment" can be done by initiative, but a "revision" must be initiated by the legislature and approved by popular ballot. Petitioners assert that Proposition 8 is a "revision" rather than an "amendment."
The problem with that argument is California's Constitution uses the term "revise" only in connection with establishment of a constitutional convention that would have broad authority to change the Constitution. An amendment is anything else:
SEC. 2. The Legislature by rollcall vote entered in the journal, two-thirds of the membership of each house concurring, may submit at a general election the question whether to call a convention to revise the Constitution. If the majority vote yes on that question, within 6 months the Legislature shall provide for the convention. Delegates to a constitutional convention shall be voters elected from districts as nearly equal in population as may be practicable.
SEC. 3. The electors may amend the Constitution by initiative.
I don't see how it can seriously be argued that Proposition 8 is something other than an "amendment," and, at least as far as I've gotten in Petitioners' pleadings, they don't make a serious argument. What the Petitioners do say is that the right to homosexual marriage is so "fundamental" that taking it away can only be viewed as a "revision" requiring legislative enactment. But this argument is completely unsupported by the language of the Constitution.