Indeed. It's one thing for Congress to regulate economic activity in which Americans engage, under its Commerce Clause powers. It's quite another for congressmen to jump into the realm of economic inactivity, telling people that they are legally required to enter into a commercial relationship with a private company.
Sure, as Lane points out, one could argue that the choice not to purchase insurance has "economic ripple effects." But that's sort of a "butterfly effect" approach to Commerce Clause jurisprudence -- one that, if taken to its logical extreme, would leave no area of our lives immune from government purchasing mandates.
Hey, if a Democrat majority can overrule the will of a majority of American citizens and tell me I have to purchase health insurance, would it be OK for a Republican Congress to do the same sort of (freedom-sapping) thing, and require everyone to buy a gun? No doubt that if the Court adopts an expansive approach to Commerce Clause powers, there'd be some way to shoehorn in an argument about the "economic ripple effects" that would justify Congress in requiring a gun-toting (or at least gun-owning) citizenry.