4)
as the governments, in an attempt to maintain their revenue, continue to push for more control over the vape industry, I can see the total banning of ejuice flavors.
Because the pod systems seem to really be taking over (partly, in response to ignorant people associating the vapor in the same classification of analog smoke & manufacturers evolving to make vape products stealthier), I can see several things developing:
1) Larger, yet more compact internal batteries
2) more efficient use of available space for liquid(s)
3) in response to the flavor ban, I believe there can be designed a pod system that could contain not only a flavorless eliquid, but a compartment for flavoring as well. liquid & flavor gets mixed automatically by the pod just prior to injection into the coil.
4) Either new companies, or branches of existing companies existing for the sole purpose of providing "baking" or "cooking" flavors which could specifically be designed for such a "dual capacity" device as above.
5) existing eliquid companies, selling not only unflavored eliquid, but also "flavors by the ml" for mixing after purchase (I'd buy a 30,60 or whatever size of eliquid, and also purchase a specific amount of flavor in 30, 60 or whatever compatibility size) mix at home, but with pre-produced flavors for a specific volume of liquid