The California Supreme Court has upheld Proposition 8, and also ruled that the same-sex marriages performed during the Rainbow Window in 2008 are legal and valid.

Update: From the Los Angeles Times:

The California Supreme Court today upheld Proposition 8’s ban on same-sex marriage but also ruled that gay couples who wed before the election will continue to be married under state law.

The decision virtually ensures another fight at the ballot box over marriage rights for gays. Gay rights activists said they may ask voters to repeal the marriage ban as early as next year, and opponents have pledged to fight any such effort. Proposition 8 passed with 52% of the vote.

California Supreme Court website (if you can get in) with the ruling posted is here.

Per Calitics, the ruling on Proposition 8 was 6-1, with only Justice Moreno dissenting. The existing same-sex marriages were unanimously upheld, however.