Devil said:
How long do you believe it will take before we have...
1) A female president
Probably within 12-16 years, would be my guess, as long as more Hillary Clintons emerge and fewer (MUCH fewer) Bachmann's try to play the game.
Hillary Clinton was a very viable candidate for President regardless of gender, and as generations X, Millenials, and post-Millenials start controlling the vote (assuming we're not crushed under the weight of the Baby Boomers first), they'll be some pretty drastic shifts in politics.
Ah ha ha ha ha ha ha ha ha ha ha... ha ha ha ha.. ha ha... ha...
A religious leader has ruled the world in some form or another for the entirety of recorded history. Even if the leader hasn't been "chosen" or "special" in any way, they at least observed the most mainstream religion of their followers.
It would be the holy grail, though, so to speak. An Atheist President would have a much more objective view, assuming their beliefs weren't "everybody who believes in God is an idiot."
I would love to see it happen (I'm an Atheist myself), but it won't. Probably not until people truly start accepting science as the defacto way to describe the Universe, and not a very large book. The aforementioned death of the Baby Boomers will help somewhat, but ignorance is a hard thing to kill off when you can't actually kill it off.
3) A homosexual president
I'd say it's possible to have one within the next 50 years. Homosexuality is tolerated a lot more than atheism in the country, partly because you can still be homosexual and go to church. Well, that and homosexuality is a lot less threatening than atheism. If you're deeply religious homosexuality becomes a ticket to Hell - and since the vast, vast, VAST, majority of homosexuals are pretty non-violent, you can simply let them do their thing and reap Heaven's rewards for being straight.
Atheism, though, oh that's beyond a ticket to Hell - it's a challenge to your subjective construction of how the Universe operates. People have a lot of internal psychological crisis when they don't have an afterlife to look forward to, or get told that their actions are pretty much their exclusive responsibility. Reality caves in on itself for the weak-minded.
Again, contrast that with a person who "chooses" to be homosexual against God's Will - implying the Universe operates perfectly according to a deity's desires.
4) You name other accomplishments and how long it'll take. (Other races, beliefs, you name it)
Muslim President - It's either going to be within the next 50, or over 150; depending on how much ultra-Conservative bullshit my generation and Gen X can buck.
Hispanic President - 75 years, probably about the time the Latino population in the United States has completely ingrained itself in American Culture and stuck-up pricks stop getting their panties in a wad that people are willing to cross the border illegally just because drug lords are murdering people by the thousands in their home town.
World President (or equivalent) - 300 years. It's going to happen, it's just a matter of when. As technology brings every country on the planet into communication with each other within a few minutes, and the population increasing, eventually dwindling resources will result in massive wars, the deaths of billions, and finally a global government.