As people from all sides of the fence try to handicap the outcome of the two marriage equality cases the Supreme Court has agreed to hear, even virulently anti-gay Maggie Gallagher, the first leader of the National Organization for Marriage, thinks DOMA is going to be overturned:
I think Kennedy will overturn DOMA (perhaps joined by Roberts) and then uphold the right of states to refuse to accept gay marriage (i.e. uphold Prop 8).
The victories this November for gay marriage at the polls make that outcome more likely. Justice Kennedy will likely see it as not at all unlikely voters will overturn Prop 8 soon and see that as a much better outcome than constitutionalizing gay marriage.
But the question then is, will they overturn DOMA entirely or just Section 3? Section 2 says that the states do not have to recognize the validity of same-sex marriages performed in other states, while Section 3 says that the federal government cannot recognize those marriages. In the cases before the court now, only Section 3 is being challenged. The key to how all these cases turn out is what standard of review the court decides to apply. If they apply heightened or intermediate review, DOMA is gone and, eventually, so are all the state bans on same-sex marriage.