The individual mandate is not a tax . . . so the Court could hear the case to rule that it is a tax. Huh? Basically, the Court held that the individual mandate was defined as not-a-tax by legislation and therefore fell outside of the Anti-Injunction Act (which would have barred the Court from hearing the case at this point in time).
But, the legislature cannot tell the Court what is and is not a tax for purposes of deciding whether the mandate is a valid exercise of Congress's power under the Taxing Clause. And, it is a tax for purposes of the Constitution - and therefore Constitutional (so the PPACA lives).
The Court also held that the mandate is not a valid exercise of Congress's power under the Commerce Clause and the Necessary and Proper Clause. I'm still trying to figure out why they even reached this issue. Once you identify a valid exercise of power, why identify powers that Congress did not (or can not) exercise? The Commerce Clause question seems no more relevant than whether Obamacare is a valid use of Letters of Marque and Reprisal. I'm anxious to dig through the opinion to see if they address why they reached the Commerce Clause at all.
Finally, per the syllabus: "[T]he Medicaid expansion violates the Constitution by threatening States with the loss of their existing Medicaid funding if they decline to comply with the expansion." My limited understanding at this point is that Congress cannot threaten existing Medicaid funding, but only new funding.
So, there you have it - Obamacare is (pretty much) constitutional. Almost no chance I'll have an opportunity to really dig through this thing until the weekend. I have a hunch that there will be plenty of coverage to satiate your curiosity.