Will there ever be a....?

Well, first of all, we have had multiple atheist presidents (look at the current one). They say that they are religious but their past history refutes such statements (which i haven no problem with).
I think you're right with woman --> openly atheist --> openly gay. Hillary would have been excellent and if she runs she will be the top candidate for the democrats in 2016 (especially if obama wins)

 

I would say a woman, then possibly a gay president. I think it will be a while before an atheist is president.

 

This would be the order it would be in

1. Woman

2. Athiest

3. Homosexual

In all honesty I doubt a homosexual would ever be voted president.