Said it before and I'll say it again ... I reckon we'll end up with a 2 tier system of vaping.
1 will be medically approved, probably similar to first generation lookalikeys in operation, with low nicotine and no flavourings.
The other tier will be what we have now, but heavily taxed and this second tier will probably have to be fought over in court for long enough that the anti smoking lobby and big pharma will have time to try and ram it down the public's throats that only the medically approved versions are 'safe'. They never like to stray too far from their 'quit or die' mantra and their quit attempt/ultimate 'relapse'/vilification, demonisation, emotional blackmail into another quit attempt, money making roundabout.
The medical versions however, may well prove to be as ineffective as 'traditional' NRT due to the limitations.