We'll have more information as time goes by, but my personal professional medical opinion is that we're going to find out this stuff in the longrun isn't so good for you.
Neither are cigarettes, but that's not news.
There have been an untold amount of chemical analysis's of ecig vapor. Once you get past the scary statements its shown the chemical exposure rate is well below dangerous thresholds. In the long run its not about being 100% safe, its about reducing the harm factor of smoking. Why do you think hospitals in the UK not only allow vaping they allow vape shops in the hospital itself? Go look up the studies from Public Health England if you don't believe me.