Should he decide to overturn Prop 8, Judge Walker could allow gay couples to begin marrying immediately or wait until appellate court has reviewed the case. Defenders of the ban could also request that an appellate court stay any ruling.

The case is widely expected to be appealed to the Ninth U.S. Circuit Court of Appeals and possibly the Supreme Court. How any ruling is framed could affect whether and how the Supreme Court reviews it: Judge Walker could tailor his decision to California law, or take a broader tack that addresses federal law vis-a-vis gay marriage.