A note of clarification here: While the FDA has announced their intent to regulate not only e-cigarettes but all tobacco products under the Tobacco Act, this has not yet occurred. The Family Smoking Prevention and Tobacco Control Act (which became Chapter IX of the Food, Drug, and Cosmetics Act) named specific products. NOT named were such products as cigars, hookahs, e-cigarettes. In order to bring these additional products in, the FDA will need to propose the regulations (which they have already announced that they plan to do, but have not done so yet). Then, there will be a period of public comment (Regulations.gov). Finally, the FDA will announce that it has published (or decided to drop) the proposed regulation.
If the FDA does announce this as their new regulation, it will be challenged in court. The FDA is authorized to enforce laws as written, not to rewrite legislation. It’s called “separation of powers.”