People say no one would ever cut off their arm and replace it. If the technology gets there, which it looks like it will, people will think about it. They might be what you’d call an early adopter -a really early adopter- but people are going to have the option of having superior limbs, superior eyes at some point. So I think a lot of people will do it.
Someday, the ethical and legal controversies over whether bionically enhanced individuals can compete in existing sports leagues may actually make paying attention to sports interesting. We’re going to see interesting John Henry type contests in the future, except instead of competing against a steam hammer, he will be competing against a man with a steam hammer bionic arm.