Just to start with a caveat: Only a fool would predict with any certainty the way the Supreme Court is going to rule in the Hobby Lobby case.
But.
Based on some of the questions and general knowledge about some of the justices, it seems quite likely to me that Chief Justice Roberts will author a relatively narrow opinion, upholding Hobby Lobby's religious liberty rights -- based on its status as a privately held corporation.
Just based on common sense (and some of the objections raised by Justice Kagan and others), such a holding would eliminate the administrability problems that crop up with a publicly-held corporation -- whose religious beliefs are being counted? Shareholders'? the board's? what if they conflict? -- simply don't exist when a private corporation has an owner, like the Greens (whose religious beliefs are well-known and longstanding).
But there are other reasons that the Chief Justice might take this approach.
As we learned in the heartbreaking aftermath of the previous ObamaCare case, the Chief Justice takes very seriously his responsibilities to the perceived legitimacy of the Supreme Court. He might believe that a narrow ruling, declining to issue a grand, sweeping opinion to apply to corporations across the board, would reduce some of the furor.
Second of all, a narrow opinion has a better chance of attracting the support of both Justice Kennedy and Justice Breyer. One of them is needed to create a 5-4 majority, but with two there would be a solid, more seemingly "legitimate" 6-3 opinion.
Even at that, however, keep in mind that neither Justice Kennedy's nor Justice Breyer's support is assured. Justice Kennedy has a well-known reputation for caring greatly about elite opinion, and elite opinion has no cow more sacred than abortion. He may have been strongly in favor of striking down the Affordable Care Act as a whole, but in that case, "respectable" Commerce Clause questions were at stake, not visceral social issues. I suspect he's not going to be chomping at the bit to sign on to a sweeping opinion. Maybe a narrower one, applying to fewer cases, could entice him aboard.
Then there is Justice Breyer. He is a liberal, he affirmed the constitutionality of ObamaCare, and presumably supports abortion rights both as a matter of politics and as a constitutional matter. But he is also Jewish, and Jewish people -- from bitter historical experience across the world -- know well the pain of being penalized by one's government just for holding a minority religious belief. Therein lies the conflict that may well shape his thinking . . . and which may make a narrow opinion very appealing to him, as well.
So we'll see. In any case, if the Chief Justice does push this narrow approach through to a majority, we may be able to expect to see some brilliant concurrences -- with more sweeping language -- from Justices Thomas, Scalia and Alito.