Comment by JimboWales: I think that this is likely to happen within my own natural lifespan. I'm 34 now, and so in 2031, I will be 54. If I take care of myself, I should be able to live to 74-104, even given today's technology.
It strikes me as a virtual certainty that we will have massively cheap machine intelligence by then. And that's going to be, for better or worse, the most amazing thing that has ever happened on EartH.