Three things that may become really hard to get: Mods, RBAs (tanks, drippers, etc. or basically anything that isn't a cigalike cartridge), nicotine liquid.
PG, VG, flavors (especially ones originally made for food like TPA, Lorann, Cap, etc.), batteries, wire, cotton, bottles, syringes, pipettes, etc. will all likely continue to be available. Resellers may wind up having to label them in a particular way, but it's pretty unlikely that any of these will become 'impossible' to get.
While being prepared is not a bad thing, nothing is set in stone yet and the fight is far from over. This isn't the end of vaping and I'm sure on some level the politicians know that. This is a major hurdle, but I don't personally believe that this is the death stroke. We aren't going away and as long as we stay vocal and keep fighting for our right to vape, we stand a chance.