>What about genetically engeneered tissues...for mental enchancing?
Here you're suggesting neural transplants, I presume?
The particular issue that worries me with any sort of hardware enhancement is the thought of doing it for someone who will then use it only for entertainment. It's one thing to crush a beer can to prove machismo, another to crush a car. Along a more purely mental spectrum, I'd imagine it'd be hysterical to pose as a respected nuclear scientist in order to get into a safely guarded nuclear facility, just to see if I could do it. And once there, to twiddle a couple of these knobs -- leave my mark, you know.
In short, I'd suggest that dispensation of such technology would have to be very closely guarded, for safety reasons alone. And an approach like that -- giving it only to those who demonstrated a respect for its potential -- would tend to accelerate the have/have not rift in the world to such an extent that I can imagine widespread opposition -- poltical as well as civilian.
And once again, I point out that neurohacking has been going on for millennia, without the need for hardware changes. I'd want to be absolutely sure that anyone who did get hardware enhancement was already a complete master of his software. There's so much we can already do, that we don't, that hardware enhancement just seems like a lazy man's approach.
The evolution most definitely isn't over yet. But more and more, I'm starting to believe that widespread access to hardware enhancement will merely retard the emergence of true posthumans.