Personally, I think Clinton would like to have DOMA repealed as well. But even she knows that it has to be done in doses. Remember, Bill Clinton in '92 had an extremely difficult time to release the ban on Gays in the Military. He tried for an all-out change and wasn't able to get it done due to the opposition from Congress. That's why we had to settle with "Don't Ask, Don't Tell". It may not be the complete goal, but it's a piece in the right direction. Eventually, more people will see just how ridiculous DADT is and eventually repeal it altogether. Same thing with DOMA.
The same way Clinton is ambitious about Health Care, I tend to think Obama is just as ambitious with DOMA. I want to be optimistic, but I don't think it going to be fully repealed for a while. There's too many blind, bible-thumping idiots in Congress that are against anything homosexual to make that happen in one quick move. With Clinton or Obama in office, we'll probably get it to be a state issue. If that starts rolling, the fact that people can be married in Massachusetts, but not "legally married" in Mississippi, would be ridiculous. THEN, maybe people will come to their senses and repeal DOMA soon thereafter.