With celebrities, racial civil rights organizations, and even the United States president all supporting gay marriage, it is but a matter of time before it becomes legal in most states. When do you think at least 25 states will legalize same-sex marriage (give an estimation in terms of what year)?
It will only happen if Washington makes it illegal to refuse same-sex couples the right to marry, honestly. If that does not happen, then that time will be a LONG time off, at least 2030 or so. Our society has always been WAY too slow on deciding upon these important matters.
Republicans already know that they can't win on gay marriage, and some are sending out memos telling each other to support it. 2020-2025 seems about right.
Not for a long time. This issue isn't nearly as important as the economy and relations with other countries, so obviously we will deal with those issues first. The issue of same sex marriage is important, but falls short in comparison to other issues.
Once DOMA is repealed, states won't be allowed to refuse to recognize same-sex marriages from other states if they choose to continue to recognize opposite-sex marriages (which they will), so the repealing of DOMA would effectively render it legal everywhere.