Here in the UK we already have a statute, called the "General Product Safety Regulations 2005" which is very broad and covers just about everything. Other specific consumer safety legislation already ties up any further "loose ends". Add these to the "CE" marking legislation and I'm sure that e-cigs/chargers are pretty well covered already. (all of the currently available "reputable" chargers, wherever they are manufactured, already carry the "CE" mark)
However hard the press and anti's try to promote fear and wonder I doubt any further legislation other than that already in existence, will ever arise.
The idea/suggestion of adding "safety warnings" to consumer goods that are "e-cig" specific is just an example of media sensationalism, that will have it's five minutes of fame only during the very short time that "vaping" justifies being sensational.
ps. *edit - Forgot to add this - "low voltage" products are actually specified as one of the long list of items that are included within the "CE" regulations and if anybody can be bothered to look at their authentic ego batteries and chargers, they will see a very visible "CE" approval mark.