The Supreme Court on Friday afternoon set up a schedule for the filing of written arguments in the case testing the constitutionality of the federal Defense of Marriage Act, with briefing to begin January 22 and be completed before the Court holds arguments, probably in late March. The order (found here) does not set a date for oral argument. The schedule showed that the Court is treating the issue over the validity of that law separately for briefing from the question of whether it has the authority to decide that case (United States v. Windsor, docket 12-307).
Source: SCOTUSBlog. Read full article. (link)