While much has been made (and will no doubt continue to be made) of the implications this has on the cult of personality surrounding John Roberts, Randy Barnett sees the upholding of the Affordable Care Act as a conservative victory of sorts:
From then until today, most law professors have taught that the power of Congress to regulate the “national economy” is limited only by Congressional restraint, which means that the power is unlimited. ... Today, the Supreme Court definitively rejected this position by holding that mandating economic activity is not the same as regulating it, and that some means Congress chooses to regulate commerce can be improper. Today, the Court reaffirmed the traditional view that there must be a judicially-enforceable limit on the powers of Congress. From now on, Congress will need to take the limits of its own power seriously, because it can be assured that the Court will be looking over its shoulder.
I'd agree - the bill is conservative at it's heart, (not to mention this) though Will Wilkinson thinks Roberts did it to save the reputation of the court:
Mr Roberts genuinely thinks continuity, stability, public approval, and a posture of deference to the legislature are crucial to the healthy functioning of the judicial branch. The members of the court have more room to move, more freedom to interpret the constitution by their independent lights, when they are not the subject of an angry, divisive public debate that loudly calls into question the independence and legitimacy of their institution. Mr Roberts observed the livid reaction to Citizens United, as well as the liberal freak-out over the mere possibility of a ruling striking down Obamacare, and determined that prudent custodianship of the court called for a light, conciliatory touch. Indeed, my hunch (and none shall doubt my amazing intuition!) is that Mr Roberts may well have chosen to join his conservative colleagues had the court not lost so much public goodwill following the Citizens United decision
If you really want to get into the backdoor gamesmanship of all this - check this out.
Remember, though, this isn't a total validation of the law. Roberts wrote that the federal government cannot compel states to sign up by threatening to reduce their existing Medicaid funding in order to get them to expand Medicaid coverage the way the bill asks them to (you can get more on that here). Nancy Pelosi doesn't think this will hinder most states signing up, though perhaps she discounts the popular red meat politics of thumbing your nose at this, but Austin Frakt agrees:
I agree with Bernstein and Aaron and Kevin Drum (all posts worth reading) that it is unlikely many states will actually refuse the money that comes with Medicaid expansion due to the pressure they’re likely to receive from providers. But it is possible some may try, and in particular they may do so to extract concessions from regulators. “Hey, let that waiver through and we’re on board.” It’d be an ugly game, threatening the affordability of coverage of low-income individuals, but that doesn’t mean some states won’t play it.
I think now that the political game is essentially a no-win for Republicans (and it's probably not something Mitt Romney wants to talk about during the election - you know, running against the same law he enacted as Governor), most states will recognize the sound policy and go along, but then again, who knows? When this bill passed, it was thought preposterous that the Constitutionality of the law would be challenged - and yet, it lived thanks to the unknown motives of a single Bush appointee justice who could've easily went the other way.