Breaking news from CBS.com:

The California Supreme Court has overturned a ban on gay marriage, paving the way for California to become the second state where gay and lesbian residents can marry.
 
The court in a 4-3 ruling issued the long-awaited decision on its Web site, saying that domestic partnerships are not a good enough substitute for marriage. The opinion, written by Chief Justice Ron George, invalidated state laws requiring marriage to be between a man and a woman.

With the ruling, California could become the second state after Massachusetts where gay and lesbian residents can marry.

"What happens in California, either way, will have a huge impact around the nation. It will set the tone," said Geoffrey Kors, executive director of the gay rights group Equality California.

California already offers same-sex couples who register as domestic partners the same legal rights and responsibilities as married spouses, including the right to divorce and to sue for child support. It's therefore unclear what additional relief state lawmakers could offer short of marriage if the court renders the existing ban unconstitutional.