If you really want a fair popular vote over the matter, then only gay people should be allowed to vote on the issue, as it solely affects them.
As for the Federal government stepping in being a sign of the apocalypse, that is just not going to happen. The Federal government has stepped in on much larger issues. I don't see how a Federal decision on marriage is larger than slavery, or segregation, or Jim Crow laws, or even Health Care. State versus Federal power has been disputed since the founding of our nation, and it will keep being disputed long after I am dead and buried.