Seems the consensus from the experts who attended the Supreme Court's hearings today on the Anti-Injunction Act issue are that the Justices pretty unanimously expressed skepticism that the penalty was actually a tax. If true, it means the substantive issues can be decided. Neither side argued in favor of it being a "tax", so the Court retained its own counsel to ensure it had all the issues before it. Clearly, the Court is very conscious of its role in history on this case.
You can review a full transcript of the day's hearing's here...DAY ONE TRANSCRIPT, 3-26-12