Perhaps this remains a long shot. But Judge Vinson's decision to hold that the minimum essential coverage provision is unseverable from the rest of the Act, and thus that the entire ACA is unconstitutional, might have set a series of events in motion that could force the Supreme Court to show its hand--or at least part of it--sooner rather than later.
Given that a binding judicial order has now declared the entire Act unconstitutional, including scores of provisions that the federal government is currently implementing or enforcing, the United States will assuredly seek a stay of the mandate pending appeal. Indeed, the Department of Justice will likely seek such a stay from Judge Vinson himself, and if that is unsuccessful, from the United States Court of Appeals for the Eleventh Circuit.
I am inclined to think that either Judge Vinson or the Eleventh Circuit would grant such a stay. It is one thing to declare perhaps the most significant piece of legislation in a generation unconstitutional. But it is something else still to call to a complete halt any implementation of the perfectly constitutional aspects of that law based on the unconstitutionality of a single (albeit quite important) component of the Act that will not take effect for 35 months.
But stranger things have happened. And if neither Judge Vinson nor the Eleventh Circuit grant the stay, there would remain only one other place to turn: the Supreme Court.
Of course, the question as to whether a stay pending appeal is appropriate is legally distinct from whether Judge Vinson's underlying decision was correct. A justice could well vote to grant the stay while ultimately voting to declare the ACA unconstitutional. But the two are not entirely unrelated, either. Moreover, the political spotlight on the Court would be intense, potentially leading the justices to act a bit differently--knowing that, however they act, it will be understood as a signal as to how they are apt to ultimately decide the matter.
Again, I do not think this scenario is terribly likely. It is more probable that the United States gets a stay from a lower court. But the chances of the matter getting to the Supreme Court are non-trivial. And if it does, we might have a much better idea, and quite soon, of what the justices think about the ACA.