This will depend on whether Roger Penrose is right in "Shadows of the Mind".

Dangers of A-life

Bill Joy worries about unchecked proliferation of A-life technology , because technology is widely available and easy to implement and replicate, unlike in the past with CNB weapons.
Software is never 100% correct; an error could transform an A-life construct into a virus. (See "Cascade virus")
But, as we have seen with Y2K, most complex systems can function sub-optimally but correctly under the stress of buggy code or incomplete specifications.

Why will Biology merge with Technology

- The higher species will always dominate the weaker one. We cannot utilize the benefits of...
- Lamarckian evolution in our lifetime.
- Integrate what one learns into inherited A-DNA.
- Integrate what others have learned into A-DNA.

We might end up one day living in symbiosis with machines, we are already encasing our technology enhanced body in the form of perception, transportation, and cognitive enhancement devices. The next step would be to integrate them internally.

Artificial life will help us understand the impact and nature of these changes.