I think it's here to stay. However, until somebody finds the middle ground between the cheap, easy and disappointing disposables and the complicated mix of eGo, 808 and whatever connections and the intimidating array of carto's, clearo's, tanks and atomizers, it's not ready for the mainstream.
A smoker interested in vaping will probably try a Blu, Fin or NJoy disposable first. If he or she finds it wanting, they'll either take the next step and get a commercialized cartridge system or something like an eGo style starter kit, or go back to smoking. A smoker who goes straight from analogs into the crazy, complicated world of options we have, he's likely to just keep it simple and get another pack of smokes.
What the industry needs is a high performance device/system that has all the simplicity of lighting and puffing, delivers the nicotine satisfaction that smokers expect, and does it with a demonstrated cost savings over tobacco use. When that product hits the market, watch out.