Meh, cool is relative, and I only care about coolness as it pertains to me. As far as I'm concerned, vaping is cool in general because it has proven to be a good way to quit smoking for me. How cool is that?
As far as vaping dying out and being a limited-life business venture, I can certainly see it going another way....
Imagine:
Smoking has been under attack for some time in many nations, and the people making money off of it are not going to go without a fight. They'll probably fight against it up until the point when they're ready to start marketing their own vaping products. They'll still have use for their tobacco farms, they'll have brands already in place, they'll have people in powerful places to help swing regulations in their direction....and most of all, they'll have an opportunity to profit from being "the savior" for all the people they were peddling death to.
I'm no psychic, but it certainly wouldn't surprise me. Vaping won't go away if it just ends up replacing smoking. To bring this in a full circle - you'll end up having 17 year old boys vaping in order to look cool for that cute 18 year old girl. The song remains the same.