I think there would be fewer wars. I'm not saying religion is the cause of ALL wars though. What I'm saying is that, no matter what the cause of the war is, if somebody doesn't believe they'll be rewarded for dying for a good cause, they will be less likely to fight. I'm also not saying that ALL atheists are anti-war like I am. There are many atheist soldiers all over the world fighting for ideas or land or their families. But I do think that without the absolute belief that your side is right, and is the side of G-D, there would be far fewer suicide bombers, and far less absolute blind hatred.
Blind nationalism is just as deadly as blind religion, and it would still be around, but I think an entire planet of atheists would have an easier time getting past nationalism. People tend to tie their blind nationalism to their blind religion, "for God and country."
I'm also not worried about a planet of atheists not doing anything to help their fellow man. It's definitely possible to be an atheist philanthropist. Just ask Bill Gates.
The scientific progress would be ridiculous though. If you believe there's no G-d, and no heaven, and no hell, and just this one rock flying through space, and we're just lucky enough to be on it, then you'd be more interested in taking care of it because you need it to live. Somehow a certain type of religious folk have decided to believe that this planet is a gift from the heavens, and is ours to drink up and kill for fun. For some reason they want to do this as fast as possible and they love oil and hate science, gays, women, minorities, and atheists. I don't get it.
That said, I don't really care about religion either way. I just think the pope is an asshole, and extremists are assholes, and they're ruining my kickass planet. Extremists on all sides suck, but science is pretty kickass. I'll let the religions do their religion things if they let the scientists do science. I've never seen a scientist tell the pope he'll burn in hell for eternity if he prays at night.
