i don't get how people can act like this is a bad development, even if this system becomes sentient.
think about it this way, we are not sure there is a higher being that created us but we are still able to recognize the value of the natural world around us (which made us as a species possible in the first place) for our survival. now think about this hypothetical A.I., it would always act perfectly rational and have acces to an impressive amount of data on the fly without the emotional baggage a human would bring to the table. it probably would run some quick calculations and come to the conclusion that our drive to make things better and to advance our technologies in adition to our ability to think out-of-the-box would make us an invaluable asset. also, it would probably recognize the immense computation power within a human brain. it would also recognize the value of a lifeform that made its own existence possible.
at "worst", it would try to help us overcome the limitations of our frail biological existence and mortality, but since it would still need our cababilities to think new, groundbreaking thoughts (which kind of needs the individual as a prerequisit) and the computational power of biological brains there would be little danger that this would lead to some kind of borg-like future.
quite frankly, there is not much i would miss about human existence apart from the possibilty to get high from weed, but that is just me and i can understand why some people would rather live a short live filled with the joys of a physical existence than an possible eternal existence as a brain-in-a-jar which uses drones as proxies to interact with the physical world.
and to the people that throw the mass effect references around, remember that the best possible ending of the geth-storyline was them and the quarians working together with the rest of the galaxy to defeat the reapers.
