-If- I understand it correctly (a BIG if) the only thing you the consumer should see is the beginning of "age verification" which has unfortunately already proven problematic at some sites for a few people. Flavor shots (boosts) will soon disappear as will free juice samples that often accompanied purchases. Juice itself should continue flowing for the next two years for as long as the vendors remain in business. Prices should remain stable for the next year or so but substantial increases are on the horizon. Labeling might change to meet requirements but that isn't really a big deal for consumers. We could see increased scrutiny of overseas shipments depending on how ....-retentive the government wants to get. Juice manufacturers must begin complying with certain manufacturing requirements but you the consumer shouldn't realize any impact unless a favorite vendor is shut down for non-compliance but I really don't think we'll see that happen very often.
Supposedly, after August no new-to-the-market items can be "legally" sold without first obtaining FDA approval. The problem is the FDA itself doesn't know what is required for approval so it's going to be a learning curve for both them and the vendors/manufacturers, I don't expect to see any "new" products hit the market for an extended period of time. The possible exception to this will be products offered by major corporations, I'm sure they'll prosper in this legislative/regulatory minefield. Especially those who regularly lobby (bribe) influential members of congress, they'll have access to the FDA's express lane. The small to mid sized companies we all are familiar with in the vaping community will likely end up closing their doors -or- be bought out by large corporations over the next two years. Due to the cost and complexity involved with gaining FDA approval, small companies (mom & pops) simply won't survive.
For existing products, I believe vendors/manufacturers must submit inventory lists of their products and then have two years to file applications for approval of each inventoried item. Seeking approval is -very expensive- the FDA estimates the cost between $300K and $400K per application/item. For juice, each flavor is considered an item, each nic strength of that flavor is considered a "different" item and requires a separate application. This is why flavor shots will be discontinued, a juice with a flavor "boost" is considered a new item and must have FDA approval. -If- the FDA's cost estimates are accurate, for vendors/manufacturers like Ahlusion, The Plume Room, Nicoticket, Goodjuice, Charlie Nobel etc.. the cost of basic product applications alone could easily run over a hundred million dollars. This is why I don't expect many will survive but will instead close shop -or- be bought out before the deadline in 2018, only time will tell. At some point the price for retail juice will rise to cover the cost of FDA approval and compliance, I fully expect to see at least 25 - 50% increases and that doesn't include anticipated state "tobacco" taxes which, for many, could easily end up dwarfing that increase. Two years from now I suspect the average retail consumer will be spending close to double what they currently pay for juice assuming of course the juice they like is still on the market.
There is a possibility one of the pending lawsuits against the FDA might prevail and stop or at least mitigate this insanity (even if only temporarily) but I personally doubt it. The U.S. is -far- too corrupt to hope for or expect a different outcome.