DOMA is also up for a SCOTUS ruling, which is potentially far more substantive (because full-faith-and-credit will actually have force for marriages). It'll be interesting how that shakes out.
Windsor v US (the DOMA case up for a SCOTUS ruling) only challenges Section 3 of DOMA, not Section 2.
Section 3 forbids the federal government from recognizing same-sex marriages.
Section 2 says states are not required to recognize the same-sex marriages of other states.
The full-faith-and-credit clause of the Constitution gives Congress the power to "prescribe the Manner in which such Acts, Records and Proceedings shall be proved, and the Effect thereof", so it's very unlikely that Section 2 will be ruled unconstitutional.
