The next significant event to occur internally at the Supreme Court related to the ACA cases is for the clerk's office to distribute the various cert petitions to the justices' chambers for consideration. As of now, briefing is essentially complete in five of the six petitions (but for the United States's response to Virginia's petition in Virginia v. Sebelius, and the various reply and amicus briefs, which are only optional). Thus, five of the six cases are now ready for distribution.
The Court's case distribution schedule is available here. As you will see, the next distribution date is Wednesday, October 26. If the cases are indeed distributed on that date (which we can check on the Court's docket sheets), we will know that they are scheduled for consideration by the justices at the November 10 conference.
(Of course, one or more justices could ask for more time to consider the petitions, which would cause the cases to be "re-listed" and scheduled for discussion at the next conference, November 22. And justices can ask for more time still; cases are often re-listed more than once.)
In all events, we should know more about the timing of the Court's intervention very soon.