You guys are missing something:
What organic limitations?
Why do we need to upgrade? What's wrong with the way we are now? Would this new life be better such that we choose it? If so, what would be the things in the current way of life that are inadequate?
I think we would all be happier if we were able to live without weakness and illness that often plagues the human body.
Instead we would live with the weaknesses and illnesses of the mechanical body or digital world.
I like my body. Weakness, illness and all. Without the weakness and illness, strife, and otherwise negative aspects of life, our lives would be eternal bliss and amusement. Would this not get boring, eventually?
Watching, WALL-E, I was thinking, how did he come to the state he was in? He had started out as a practically emotionless robot, but over the centuries, he developed what looked like emotion. What caused him to acquire this "human" curiosity? The only answer that I could come up with, and it seems to make sense to me, is that, he simply got bored. If you think about it, all emotion could arise from boredom.
Without the twists and turns and ups and downs, a roller coaster loses its name.