I love letting my mind wander into the future like this. For me what is exciting is that we are now getting to a point in our history whereby we can address the elephant in the room.
That being; space is incredibly inhospitable, and despite the resource issue humans cannot survive very long outside of Earth's atmosphere. Even on Mars, the lack of a magnetosphere means the likelihood of getting cancer is a thousandfold of what it is on Earth.
However we are now moving into this age of transhumanism, where by we can alter and assist our biology. I don't know how future earth will look like, but I'm fairly sure future humans won't look (internally at least), anything like us.