In answer to the people who have stated that ecigs will be legalised because there is money to be made from them, I'm afraid that is the opposite of the truth.
It's mainly about who will lose money due to ecigs:
1. The pharmaceutical industry
They will lose a fortune because no one will need their less-than-marvelous NRTs. As these have a success rate of somewhere between 1.65% and 7.5% depending on whose figures you believe (ie a failure rate of about 98% to 93%), neither consumers nor doctors will want them, as ecigs used for the purpose of quitting tobacco are reported to have a success rate of 60% or better (unchecked, untested reports of poll results).
(However, I personally believe that the majority of ecig owners are simply looking for an alternative to cigarettes and, like me, don't intend to quit nicotine or quit *all* types of smoking. They are smokers but not as we know them, Jim.)
Pharma are the big issue because they have huge amounts of money available to fight ecigs, and can spread that cash around generously.
2. State treasury departments
As tobacco revenue decreases, their pain will increase. Some of them can see that on the horizon and have woken up to the fact there will be a massive hole in their budgets in a few years if ecigs are allowed to grow unchecked.
3. National treasury departments
The same is true for national budgets, multiplied by a factor of [insert large figure here]. Tobacco revenue raises billions and that pays for an appreciable part of the economy. For example in the UK it not only pays for the healthcare of ill and dying smokers, it pays for most of the health service as far as I know. The national health service is virtually free, paid for by smokers - no insurance needed.
4. Big Tobacco
Funnily enough they seem to be feeling the pain less than anyone else. In fact we don't have much evidence at all of them fighting ecigs currently. But when you think about it, they can't lose: they know the writing is on the wall for tobacco cigarettes in the West. The pressure is mounting, more and more regulations are just around the corner.
Now if a new form of smoking comes out that is apparently much healthier than combustion of tobacco, and for which they can control the supply of the raw ingredients, and that requires slick marketing (their speciality), and a large injection of funds in order to control the market (which they certainly have), and which might get around many of the new, tough regulations- you have a blueprint for a new product that BT can compete in the market with very successfully. Essentially BT can't lose, whatever happens. There is no reason to suppose that a Marlboro E-Cigarette will be any less successful than the tobacco version. There are wall chargers out there in marlboro country now.
As far as the money goes, you're talking about billions - and that's billions lost from tobacco tax. Nobody is going to let that go without a fight.