I'm in healthcare, and this is a hot topic. A lot of patients ask if they should use e-cigs. The official stance of the FDA and American Medical Assoc is that e-cigs are un-tested, un-proven, and probably harmful from unknown chemical exposure to the lungs. Obviously, its early, and no long term data on safety is available. Is it dangerous long-term? Is really bad for you? I don't know.
What I do know is that my dad used e-cigs to quit smoking after 40 years of smoking a pack a day. Nothing else worked: patch, gum, medication, acupuncture, etc. So I truly believe that when used correctly, it can be powerful tool to help people. I hope if any of your are habitual smokers, I hope you can quit, one way or another!