One of the things I've always been fascinated with is the interaction between man and machine. Particularly, I have an interest in direct neural interfaces and the promise they have for advanced prosthetics...and even for every day activities.
Every day we come one step closer.
In the world of Transpecial, Earth fitted their GIs with neural "webs" - artificial nervous systems that allowed them to interface with their weapons and also enhanced their reaction time and strength. Neural webs have also been used to allow people born on Mars or Luna to function in Earth's higher gravity. It's now been discovered that they make the ultimate piloting interface.
However, there are downsides. The Martians believe that the webbed soldiers have been brainwashed and conditioned to shoot "anything not in an Earthforce uniform." While this may be true, it's unlikely to be a result of the web. As a result, though, neural webs are illegal on Mars. People fitted with one are not permitted to immigrate - or even to land on the planet. Webbed veterans find themselves unable to find employment even on Earth. Humans will always have their prejudices, and people with superior physical capability? They're going to be victims of them. Something to think about, perhaps, before we start going that route by any means.
On the other hand, it is very likely that some kind of enhanced humans will be with us, be it through technological or genetic means. Very soon.