Not entirely. First, e-cigarette is a vaporizer. It is miniaturized, but it is still a plain vaporizer. True, it is designed to vaporize pure substances, but you can vaporize them as well with a normal size vaporizer, which is often much more sophisticated, better controllable, and hence also safer in many aspects.
The health risks I mentioned in my previous post apply to e-cigs too. The problem is that these risks are very little studied, the time e-cigs and vaporizers are in use is rather short and statistical data about users practically nonexistent. It is true that vaporizers considerably reduce many risk factors of conventional smoking, making it so appear as a harmless alternative, and potentially leading to stronger abuse. That's probably currently the biggest risk. Well, in fact the biggest risk is that e-cigs will take over standard tobacco and ruin the tobacco industry, and cut short one of very profitable source of tax incomes for the governments, but let's aside this part.
Another health risk of e-cigs is that the cartridges and the devices are not yet under strict regulation, so they may often contain or generate dangerous substances and byproducts that may be more hazardous for your health than the product self.
However, it is likely that e-cigs will gain popularity, so perhaps in 20-50 years we'll have sufficient statistics, and will probably see some of the suspected hazards fulfilled, and other unexpected appearing.
That told, by using e-cig instead of tobacco cigarettes, or vaporizing instead of smoking, you certainly avoid a lot of ugly stuff, but it would be naive to believe that it is perfect for your health and poses absolutely no risk. The risks are simply not well studied yet, so it is premature telling it is safe. It is up to every individual to chose whether the use of the substance is worth of it or not.
