Doomies

Any day now.

Doomies is the collective name for the Doomsday Prepper subculture. Since the first humans stood upright and gazed in wonder upon the world, someone behind them muttered about how this was all going to end in calamity, and soon. Doomies continue this ancient tradition of proclaiming that the end is nigh, whatever form that might take. They are a motley bunch, ranging from religious zealots to concerned citizens to lost souls.
The Doomies know that when the end finally comes, they are the only ones who will be ready for it - even if they will never agree with each other what exactly that will be.

The End Is Nigh!

You can't trust that Computer . Believe me, it'll be the death of us all.

The Doomies subculture has changed as human society has and new things give rise to new fears. From the wrath of god to nuclear apocalypse, there has always been something for Doomies to cling to as the End. In the Megacorpolis, the Doomies mix terrors both old and new with a cocktail of social anxiety, the loss of identity and the corporate grind.
Doomies are split into two groups:

Casuals

I just bought a fresh batch of gear! Want to come check it out?

To the Casuals, the Doomies subculture is a lifestyle and a brand. It is an identity and a life-style. These Doomies collect the latest brand of survivalist gears, kit their homes with redundant air filters and probably never use any of it.
Casual Doomies tend to cluster together, reinforcing each others identity and providing a clique to show off their stuff.
They are by far the most numerous of the Doomies and it isn't unusual for people to dabble in it.

Survivalists

Grim and serious, the Survivalists don't play games. To them, the apocalypse is coming and they will be ready for it. Unlike Casual Doomies who put a premium on having the latest and greatest stuff, Survivalists prize functionality. Any Survivalist worth his salt will have an eclectic set of survival skills, typically far beyond what any Casual will have.
Survivalists hate Casuals with a fiery passion. Most other Doomies either stand in awe of the Survivalists grit and skill, or find them a bummer to be around.

Games are for children. If you don't take it serious, you're gonna get hurt.

by Johny Mnemonic (with slight alterations)

Between the Survivalists and the Casual, the Doomies are further split between what exactly they think the end will be. Each group us certain that they are correct and that everyone else are delusional idiots. There have been a few attempts at creating a sort of unified end-time theory, but that usually only makes every group angry.
Some groups are new, fears spawned as technology provides new and exciting things to worry about, but some of the classics never go out of style.

Aliens!

On-and-off aligned with the various UFO groups around Megacorpolis, Alien-Doomies believe that aliens have visited earth and are planning something. Whatever it is, it probably isn't good.
After all, whenever one human culture has met another of inferior technology, it has never worked out well.

AI!

When construction began on the Computer, Doomies saw an resurgence about fears about the singularity, AI and robot revolutions.
They've spent the decades since in decline while insisting that it's going to happen at any moment now.

Gods!

Out of all the Doomies, it is the religious type that are the most likely to want the end to come. They see the apocalypse as justification, proving them right and everyone else wrong - and dead, but they don't seem to mind that.
Exactly what form gods' wrath will take depend on the faith in question and they get along with almost no one outside their own group.

Spiders!

Cybiders are a common sight around the Megacorpolis, doing everything from construction to babysitting.
The greatest marketing campaign ever wage had manged to convince people that spiders were not scary. But some people know better. These Doomies know that the world will soon be webbed.

Nukes!

Death by nuclear fire almost seemed quaint for a time, with so many other ways the Earth seemed about to implode.
But the end of the war between the remnants of the Russian Federation and the Canadian Empire reignited fears of nuclear death. The great wasteland wall left in its wake is only a preview.

Dinosaurs!

Genetic technology has advanced in such a state to bring back the dead and put them in commercials.
The Dinosaur Crisis of the past decades has seeded the world with huge, flesh-eating killing machines for the purpose of PR and marketing. Some Doomies see not the realization of a delightful childhood dream, but cold reptilian death for the world.

Almost Right

For a time, it looked like the Doomies were right. The planet was a handful of decades from turning into a shriveled husk and all news was bad news.
To the great disappointment of Doomies everywhere, the end never came and climate apocalypse was averted. To this day, Doomies refer to this point in history as that time they were "almost right".

by Johny Mnemonic (with slight alterations)

ArmaggeCon

Doomies have moved further into the mainstream with every near-miss and it has become profitable enough to exploit them. Movies, merchandise and conventions have sprung up around the Megacorpolis to go with the actually useful survival gear.
The largest of these is the ArmaggeCon, a week long convention about survival gear and gear, but mostly for people to make a buck.

by Johny Mnemonic (with slight alterations)

Fallout Fashion

Several corporations have started marketing and selling apocalypse-apparel with the Doomies in mind. There's a category for almost every stage of every kind of apocalypse, and more than one cult are frequent shoppers.
While the apocalypse-fashion is very popular with the Casual Doomies, wearing it near a Survivalist will start a rant.

For some Doomies, waiting for the end isn't enough - they intend to see it happen. If gods and devil can't keep to a schedule, they'll just have to take matter into their own hands.
The apocalypse has been delayed so many times already, after all.

by Johny Mnemonic (with slight alterations)