Unfortunately this is incorrect. The government pharmaceutical licensing agency only just failed in an attempt to ban e-cigarettes, which was blocked in effect because the government changed. If the old one was still in power, e-cigs would now be banned (the new lot didn't want more regulations). In one year's time, the agency will go to law to have ecigs banned in the UK. At that time we will need to fight or say goodbye to 99.99% of products. You will be able to buy a cigarette clone model with a tiny battery, and one or two mild flavours of eliquid, probably with low nic strength. And that's that.
Debate, logic, reasoning or whatever is not relevant. The pharmaceutical industry will lose more and more income from NRTs as e-cigs become more popular, and they are the ones trying to get a ban. Governments are at this point neutral. However the pharma industry has a strong influence over certain government departments, so their agenda is promoted.
Tax will be applied when the pain starts to bite. Since tobacco tax pays for the entire NHS, I believe, then when tobacco tax revenue has fallen by 25% you can expect a reaction. Before that, no doubt.
You can probably see that when 25% of smokers have converted to ecigs - as they will, the only question being the timescale - the financial implications will be interesting. We're talking here about a massive black market of course, if ecigs are banned. Most people will continue to buy on the web, but their supplies will be mailed in from Holland or wherever.