FWIW, the opinion was written by a Clinton appointee.
I personally think that since the mandate was central to the legislation and in fact is the fundamental lynchpin, I don't see how the rest of it can be constitutionally implemented.
The states were suing on this one. The mandate was actually favored by the Insurance companies as this was going to ultimately be a full employment bill for health carriers (not doctors).
With the mandate gone and the rest of the legislation intact, the insurance companies will be screaming bloody murder. They will file their own lawsuits, and speaking as an insurance defense attorney, these insurance companies have armies of lawyers.
I agree, if this stands the law will never see the light of day from a practical standpoint. IIRC, even the administration has admitted that if the mandate goes down the whole thing goes down because there is no money to fund it. Healthy people will just opt out until they need it. The fines were small I think, so without any real money going in, it will collapse under its own weight.