According to the official California election website, the proposition does two things: changes the California Constitution to eliminate the right of same-sex couples to marry in California and provides that only marriage between a man and a woman is valid or recognized in California.
The voter initiative came about as a result of a 4-3 California Supreme Court decision last spring which declared that restriction of marriage to heterosexuals was discriminatory. Opponent groups moved immediately on November 5 to file a petition to request that the California Supreme Court strike the measure down as unconstitutional on "equal protection" grounds.
Much of the political and entertainment establishment opposed the Proposition. Almost every Democratic Party luminary went on record against it, including Governor Arnold Schwarzenegger, both U.S. senators, and the mayors of San Francisco, San Diego and Los Angeles — along with the editorial pages of most major newspapers. Now that it has passed, predictable opposition has come from all of the same quarters. For Example, a Huffington Post piece from Paul Katz called it "homophobia in plain sight. Nothing else."
While pro-traditional marriage advocates are elated, the proposition still leaves much damage to our system of government unaddressed. By having voters arbitrarily define the term "marriage," they have also granted the premise that it can be just as easily re-defined by democratic opinion at a later time. Few pro-family activists seem to question the basic premise of having judges usurp a legislative function as they did. This whole issue should have been redressed in a simple manner by the state legislature, rather than by a voter initiative.
Elsewhere in the country, Florida and Arizona also passed same-sex marriage bans.