The American Heart Association has joined the ranks of other groups who are calling for more regulation of e-cigarettes, according to an article in the Toronto Star. The association is particularly concerned about the health of young people who appear to be targeted with a variety of flavours and devices.
The City of Toronto Board of Health has also asked Ontario to ban e-cigarettes wherever smoking is currently prohibited. It says if the province doesn't do it, the city will. You can read more about that in this Toronto Star article.
For some background on why tobacco is so addictive, you can watch these video presentations by Dr. Andrew Pipe.