Come this Monday, everything that is within the scope of power for the U.S. Department of Justice will be instructed to treat same-sex and opposite-sex marriages as equal. This news paves the way for nation-wide acceptance of same-sex marriages. The states still withholding rights from same-sex couples soon won't have a leg to stand on.
This means that every DoJ related protection that is afforded to spouses in opposite-sex marriages will apply to those in same-sex marriages, as well. Everything from the right to decline to give testimony that might incriminate their spouses to the ability to file jointly for bankruptcy. Even prison visitation rules are being applied equally to all orientations.
What does this mean for state laws and regulations that ban same-sex marriage, or even the recognition of it? It means their days are numbered. If a married couple can receive full spousal rights in one state and not another, then that is a very obvious violation of the equal protection clause of the United States Constitution guaranteed by the 14th Amendment. There is absolutely no way to defend the discrimination by some states, but not all, with any degree of intellectual honesty.
Now we just wait for the lawsuits to begin.