There have been studies done and nicotine is only dangerous if consumed in large quantities. There are plenty of vegetables that are sources of nicotine that people eat regularly, i haven't seen any reports of aubergine related nicotine deaths yet.
the e-cigs that were used in this study i believe were the over the counter variety produced by the big tobacco companies, so it's not surprising that they are full of crap chemicals.
Most vapers are using eliquids produced here in the UK, and are as safe as they come. The ingredients used in them are used in plenty of everyday foods and things like asthma inhalers.
http://en.m.wikipedia.org/wiki/Propylene_glycol
http://en.m.wikipedia.org/wiki/Glycerol
Food flavourings
Nicotine
Obviously the addictive nature of nicotine is the bad apple in eliquid, but it is much, much safer to get your fix vaping than it is to smoke regular cigs.
I must admit that I hadn't known about the aubergine containing nicotine. The question is how hard is an aubergine to light and which end do you smoke it from?
@Dave the Smeghead you are far more likely to be harmed by the fumes from cars when walking down the street than you are by an e-cig.