I'd like to say that he's wrong. I want to dismiss what he has to say as crazy. In fact, my heart tells me to believe that music will always be a human art, that the human voice and performance will always trump that of a robot or software simulation. But my mind and my gut tell me that he's right about this. What I would like to be true isn't necessarily what will be true.
You can already see the trend in current pop music. A large segment of the top rated pop songs has at least some use of a vocoder (such as Auto-Tune) - if not to create a outright robotic sound, then to make mediocre or even dreadfully off-key singers able to make their pitches.
Just listen to any song by Ke$ha. If you want to hear what she really sounds like without a machine to keep her on key, click here. It does seem like modern pop-stars are becoming so lazily dependent on machines that the artificial sound has itself become part of the pop culture.
I believe "Hatsune Miku" will only get better in terms of realism. "She" will become more human in "her" sound. "She" will learn to "speak" better English. And there will be a whole slew of different "singers" cut of the same virtual cloth. We've seen what CG animation has been able to do in just a few years, and I believe we will see this Vocaloid technology improve at an exponential rate.
Here is a search for Hatsune Miku videos on YouTube.
I suspect this technology will also exacerbate the current trend whereby fewer young people will bother to learn music (because it is hard work). I also believe we will see less young people taking up traditional instruments or singing in choirs. Just as fewer kids spend their summers actually riding bicycles and playing football, instead opting to simulate these same activities virtually on the couch with a video game - I think this paradigm shift will ultimately have a negative impact on music.
I hope I'm wrong about that. When music becomes less human, I think we will likely soon respond in kind. The richness of the vox humana is becoming the shallowness of the vox robota.
Hopefully, the machines won't keep us in pods and use us as batteries any time soon...