It's perhaps worth pointing out that this software is for detecting the presence of any old face, not for detecting a particular face, such as you or Osama Bin Laden.
Right, detecting who is in a picture would be "face recognition". Good point though.
Does it only do human faces? Could it detect my dog, or a Cubist rendering? (Face detection in non-photographic art could be quite lucrative, I imagine.)
In general, just human faces. But I had a friend tell me they drew a picture of a face on a whiteboard and it detected it.