I'm very wary of this post for being so vague and not linking to an argument, but I'll throw my two cents in. :)

The future will not have a firm concept of individuals.

I see two ways to interpret this:

1. You could see it as individuals being uploaded to some giant distributed AI - individual human minds coalescing into one big super-intelligence, or being replaced by one; or
2. Having so many individuals that the entire idea of worrying about 1 person, when you have 100 billion people per planet per quadrant or whatever, becomes laughable.

The common thread is that "individuality" is slowly being supplanted by "information" - specifically that you, as an individual, only become so because of your unique inflows of information slowly carving out pathways in your mind, like how water randomly carves canyons over millions of years. In a giant AI, all the varying bits that make up one human from another would get crosslinked, in some immense database that would make Jorge Luis Borges blush; meanwhile, in a civilization of huge, huge populations, the value of those varying bits simply goes down, because it becomes increasingly unlikely that you'll actually be unique enough to matter on an individual level. So, the next bottleneck in the spread of civilization becomes resources.

This is probably my first comment on this site - feel free to browbeat me if I didn't get my point across well enough.