You heard it here first. The votes of Sotomeyor, Ginsburg, Kagan, and Breyer are assured. Roberts and Kennedy will not like the law (well, who does?) but will vote to affirm it on the following grounds:
1. Health care requires construction of a huge complex of hospitals, clinics, drug testing and delivery, medical schools and research facilities.
2. All of this is fundamentally available, particularly on an emergency room basis, to all persons whether they have health insurance or not.
3. But to ensure the ordered provision of health care, persons who currently don't anticipate a need (which could change tomorrow as the result of an accident, say). for health care, can't be allowed to take that gamble.
4. Sooner or later the healthy people have to pay for those that are sick, yet when those who don't pay when they're healthy will still be provided for, at least in a rough in ready way, by the system, when they fall sick or become the victim of accident.
5. This is fundamentally no different than the Social Security or Medicare systems.
6. The fact that the insurance that must be purchased is technically issued by private companies is of no constitutional significance, as the insurance companies have been forced to submit to heavy regulation, and whether Congress choose to run the reform through existing financing vehicles, or set up a new procedure, was up to Congress to make.
Roberts will write the opinion, as he won't want to be excluded from having his name on a case of this importance. He'll also try to craft some limiting feature -- look for it to be the uniqueness of the health care delivery and finance system. Scalia will concur, grousing about this and that detail, but he won't bring himself to dissent.
Thomas and Alito, who curiously have spend almost their entire careers inside government or academia, yet seem to hate both systems, will dissent, because it wasn't done this way back in 1918.