Well, the good news is they won't self-replicate. We still gotta
  build them. Even if they build themselves someday, they'll still
  have factories of some kind. Perhaps swarm AI might be an issue
  though. Nano-sized. They could be an issue, like little robotic
  bacteria in a way. But larger-scale AI should be ok. Keep the
  numbers under control and I think we'll do fine. Fingers crossed
  smile emoticon