I haven't read all the posts above.
I have a positive view of the world that my progeny 87 years from now will be living in.
If we subtract 87 years from 2013 we find ourselves in 1926.
Medicine, technolgy, you name it, have all advanced to the point of being almost unrecognizable to those 1926 folks, many are still living and can testify to what they have seen.
Assuming that technology and medicine advance at a faster pace than they did during 1926-2013, it will be unrecognizable to people today.
I have grand, and greatgrand-children that will be there. When I hold their little hands I think about things like this. By the time the great great grands come along I will be long gone.