Having a story involving a new breed of humans with enhanced skills would be very cool, especially if you can't see the changes on the outside.
Years ago there was a series on TV that involved an evolved version of mankind with that possessed superior intellect and were eventually aiming to overthrow the dominant homo sapiens. At the time of the TV Show their numbers were small, but growing. I believe they were also resistent to disease, stronger, more intelligent, aged older and in better physical/ mental condition, quicker reflexes, etc.
Maybe you can use some of that for your ideas, possibly adding in telepathy as well that would allow them to communicate without speech. Just imagine of the tactical advantages that would give when such a group comes together (with 1 in a million it'd be easier to find others with such an ability as well), and want to find a place to call their own where they can settle.
Possibly plot lines you can explore is finding out what caused them to be like this, have them find an (isolated) place where they form their own community, possibly give them a couple of bad traits like having very dominant men that easily get into fights with one another (having sources that create drama is great for a game), have them get attacked by normal humans who fear them, etc.
Since it plays in the far away future you could even involve a plot line with aliens trying to take over the planet through stealthy methods. You could have a storyline where they're never actually visible, but could be the ones pulling on the strings behind the scenes. You're already going to have scifi elements anyway since it plays in the future, and you could explore that more as well. For all we know it's actually another species alltogether that caused the armageddon, and these new humans could be an unexpected, or possibly intended, side effect of whatever they did to cause it all.
All of the above were just some ideas from a brain storm I had, feel free to use or reject as much of it as you want.