[ddantas]

Does that mean growing your own corn is now illegal?
Yes, in one of the cases the Court cited, Wickard vs. Filburn, he was growing wheat for his own consumption, and the answer was, yes, the federal government can regulate it because it affects the interstate commerce. This case was an affirmation in some ways of that precedent.

[Noachian]

...Wickard vs. Filburn, he was growing wheat for his own consumption,...

The way I understand it, in W vs F, the farmer signed a federal contract to grow only so much wheat, and by growing more he violated that contract.

But, the people in California using medical marijuana signed nothing, so the Wickard precedent is a matter of apples and oranges and shouldn't have been used.

It seems that the SC is grasping for straws, in this case, to involve itself into states rights. A clear violation of the 10th Amendment.