The only hardware I can possibly see being regulated (or at least attempted to be) are attys and VV/VW-type devices specifically made for vaping (like eGo batteries). Everything else (resistance wire, loose batteries, wick material, etc) is used by far too many other, completely unrelated, industries for the FDA to impose any kind of regulation on them, or to even consider them "tobacco accessories". Even things like DNA 30 chips couldn't fall under their regulation, because on their own they're just fairly basic DC-DC power regulators (something that most digital devices have in one way or another.)
Even mechanical mods would be difficult or impossible to regulate: no matter how shiny that copper Stingray is, at the end of the day it's just a threaded metal tube. Even if a vendor couldn't sell it whole, there's no way the FDA could stop them from selling the individual metal tubes, threaded endcaps and a dead-simple mechanical switch separately. In general, these are not complicated devices by any means. Can't sell a 510-threaded end cap? Okay, places will sell a cap with a hole in it and a tap-and-die set so you can thread it yourself. I'd imagine someone with a few tools around the garage could even build perfectly functional drippers at home without much technical knowledge. I suppose they could try to ban things like the VaporShark...but I don't see how they could ban selling the individual components (most of which can already be found at places like Mouser or Digi-Key). And they certainly couldn't ban PDF's of instructions on how to assemble it because that falls squarely under 1st Amendment protection. Ultimately the majority of devices and components fall way outside of the scope of the FDA, and most of them couldn't be banned or regulated simply because it would have a serious impact on hundreds of other industries.
I can't see how the vast majority of vaping hardware could be regulated by the FDA, and I suspect most of it will be removed from the final regulations. Keep in mind a lot of this stuff originally started somewhere else anyway. It was already around before vapers started cobbling stuff together, and a lot of it will continue to be available from its original source either way. I'm not saying we shouldn't worry about it (we should be concerned about everything the FDA proposes in regards to vaping), but their main focus will almost assuredly be eliquid (and especially the nicotine aspect) and purpose-made atomizers/clearomizers/your-topper-of-choice...maybe followed by the other stuff waaaay down at the bottom of the list if they really get desperate. If they even implied that they'd try to ban or regulate things like Kanthal or 18xxx batteries, they'd have dozens or hundreds of industries (like model/RC hobbyists, the aerospace industry, the computer industry, etc etc) banging down their door.
Keep in mind these are just my opinions, based on my own research and brainstorming on the matter.
I hope it doesn't get that way with vaping but if it does, we now have some ideas.
