Trophic levels, trade and the Terminator
As an AI aficionado, I've had my fair share of debates about the Terminator scenario. Perhaps blindly, I'm optimistic about the possibility of being enslaved or eradicated by robot overlords. Here's one possible response.
Why would the machines be so obsessed with the idea of dominating or eradicating us? They'll occupy a completely different ecological niche. They'll almost certainly have entirely different energy/resource requirements, be free from human claustrophobia and may not even be embodied at all. They won't care if the earth runs out of resources because they'll just photosynthesise or transduce faeces. So, even if it turns out that aggression is a necessary component of intelligence, it just doesn't make sense that they'll want to wipe us off the face of the earth any more than we're determined to wipe bacteria off the face of the earth.
Unfortunately though, that's a somewhat spurious parallel. We aren't in competition with bacteria - in fact, we depend on them. In contrast, there's less reason to suppose that intelligent machines will depend on us. In that case, the better parallel might be the relationship we have with chimpanzees. That would be more cause for concern.
So the best case scenario would be mutual dependence and integration with the machines. It's no coincidence that trading partners rarely go to war with one another. However, we're going to have to find something we're better than machines at in order to have something to trade. Perhaps we could elevate captchas to a form of poetry?