On Tuesday, the Supreme Court will be issuing opinions in any number of cases that are still to be released. Foremost among them (for many court watchers) will be opinions in Shelby County v. Holder (voting rights), Hollingsworth v. Perry (Proposition 8 - gay marriage), and United States v. Windsor (Defense of Marriage Act).
Although one can't say for certain which opinions will be released today, it's likely the gay marriage opinions will be handed down later in the week. They were argued relatively later in the term and also given their controversial nature, are more likely to come at the end. SCOTUSblog also has live coverage of the event and video from outside the courthouse is being livestreamed.