Update, 3:30 p.m. ET
The Supreme Court did not take action Friday on the 10 same-sex marriage cases it has been considering for the coming term.
According to SCOTUSBlog:
Original post follows
The Supreme Court will decide Friday whether to take up three landmark cases in a decision that could further expand gay marriage rights in a big way immediately.
At Friday's closed-door session, the justices will choose the agenda for the rest of this term. Up for debate: ten petitions dealing, in turn, with Proposition 8, the 2008 Calfornia ballot measure that prohibited same-sex marriage, the Defense of Marriage Act, the 1996 federal law defining marriage as between a man and a woman, and Diaz vs. Brewer, the Arizona injunction prohibiting same-sex couples from receiving domestic partner benefits.
For each of these cases (DOMA actually comes to the Supreme Court by way of five separate challenges), a decision not to hear the cases would actually do more.
For Prop 8, the Court's decision could have an immediate impact. As things now stand, a California appeals court struck down the voter-passed law in 2010, and if high court decides not to hear the case, gay marriage in the state would become legal immediately.
Otherwise, a decision would likely come in June.
The Court's (non)action on DOMA would also have a major, if slightly less immediate impact for gay couples. The law allows Congress to pass federal laws that treat same-sex married couples differently than heterosexual couples, including federal benefits, taxes, health care and the due process clause of 5th Amendment.
Although it's likely that the court will hear petitions against DOMA, if they don't, than same-sex couples married in states where same-sex marriage is legal will be treated exactly as heterosexual married couples under federal law.
Otherwise, the Court would have rule on the constitutionality of Section 3, which defines marriage as "one man and one woman."
Finally, Arizona's Diaz vs. Brewer deals with an injunction preventing the execution a law prohibiting the unmarried same-sex partners of state employees from receiving domestic partner health insurance benefits (gay marriage is illegal in Arizona). If the Court decides not to take up the case, those partners will continue to receive partner benefits.
The justices are expected to announce their decisions on Monday, but the word could come as early as Friday afternoon.