[...] I see the FDA getting involved within months. Big fight ensues. Shipments get halted. FDA orders enforcement. E-cig makers ask, "What will please you, oh Big Brother." And the FDA, after hearings, says the devices must be childproof, tamper-proof, fire-proof and not useable for any but the express purpose of delivering nicotine vapor. A 2mg maximum on nicotine strength will be imposed. Higher strengths will be declared addictive and too dangerous.
E-cigs will then be sold in packs of five, and tobacco taxes will be the basis for their taxation. No refilling. No carts. No battery to charge. Just a single-unit metal tube containing battery, atomizer and liquid cart, ending with a small hole for inhalation.
And, frankly, we might be lucky if even that survives government scrutiny.