Damon Root of Reason sees a connection between the way the Supreme Court ruled on Obamacare and how it could rule on DOMA:
"...So let’s assume DOMA will be the first gay rights case to reach the Roberts Court. Is Socarides’ right that the chief justice will again show "a willingness to break with his more conservative colleagues"?
I wouldn’t bet on it—at least not if we take Roberts at his word. Remember that Roberts framed his vote upholding the Patient Protection and Affordable Care Act as an exercise of judicial restraint, writing in his opinion, “It is not our job to protect the people from the consequences of their political choices.” I don't see why Roberts wouldn't rely on that same principle and vote to uphold the Defense of Marriage Act. Both Obamacare and DOMA are duly-enacted federal laws, after all.
If you cheered the chief's ruling on health care, don't be shocked when he grants the same deferential treatment to a federal law you don't like."
Legal scholar Jonathan Adler over at the Volokh Conspiracy legal blog agrees.