The problem with nicotine is that even if it is good for you in little doses, small amounts can get you hooked and develop a psychological and physical dependancy on an outside source. It's much better to avoid nicotine in general, along with any other addictive substances.

Though I do approve at least of reducing the possible damage done to smokers. Plus, if you have a girlfriend who smokes e-cigs she doesn't have a mouth that tastes like an ash tray.