Is Artificial Intelligence a Threat?

I encourage every one to give a close reading to MIRI & Bostrom, and to avoid any merely shallow critique. They deserve a close reading, and likely have given it consideration.

For a different perspective from Bostrom's see Land's

http://www.xenosystems.net/stupid-monsters/

Of course it is. Though it could be said the same of natural intelligence too.

What Artificial Intelligence?

Yes. It is a threat.