I addressed this in the comments section of my post on the Supreme Court opinion yesterday, but I wanted to reemphasize the issue, because I'm still seeing it pop up today:
Article I, Section 7 of the Constitution requires tax bills to originate in the House of Representatives, and it was the Senate version of the Obamacare legislation that became law.
"Aha!" you might say. "The Supreme Court held yesterday that Obamacare was valid as a tax, and not a mandate, so doesn't that mean that the law really is invalid after all?"
Not so fast. The Democrats employed a number of tricky maneuvers in order to get this monstrosity of a bill made into law (including lying to the American people about the fact that it is actually a tax!), and one of them was for the Senate to take a bill that had already passed the House and tack the Senate version of Obamacare onto it. Therefore, the bill that the Senate passed was technically a House bill, and in compliance with Article 1, Section 7.
Allahpundit has a good explanation over at Hot Air if you want more background on this.
ObamaCare is, unfortunately, valid law. But remember, we the people can do what the Supreme Court did not, at the ballot box in November.