While The Fixed Gear Phenomenon (tm), or trend if that's you want to call it that, is currently taking over the world by storm, even now in the times of globalization where information travels around the world at the speed of light, in different cities and countries the popularity of FG bikes is still at very different levels.
From what I've gathered, places like San Francisco, NYC and Tokyo are way ahead of lots of other places on the curve but here in Europe particularly we've been pretty slow in catching up. While the scene in London, for example is growing fast, cities where you would think such new things would catch up quickly, like Paris, Berlin, Milano, Barcelona and Amsterdam, are all still lagging behind when compared to cities in USA or Japan. This could of course be a good or a bad thing, depending on where you stand, or whether you care at all.
But, as every thesis has its antithesis, every trend has a backlash just waiting around a corner. As a proof, , here's a link to a rather nasty article from SF Bay Guardian from 2006 which presents some early signs of the inevitable backlash an shows how far ahead SF is in this.
Here's some good quotes if you're too lazy to read the whole thing:
"Sounds like a pain in the ass. If you're like me, the first question that comes to mind is "why?" Well, the modern SF two-wheeled steel, aluminum, and rubber hipster fashion accessory has its roots in racing, like other wheeled vehicles that don't really translate to street usage."
"Like trucker hats and PBR, what started as a bike messenger thing has become a fashion statement and status symbol. You've got kids in the Mission with the left leg of their jeans rolled up, a little biker hat on crooked, slip-on Vans, and a brand-new fixed-gear Bianchi; and they don't know their ass from a light socket."
"Riding a fixed-gear is like handicapping yourself. The bikes are so awkward to ride that not looking like an idiot while riding one is an accomplishment. It's like riding a three-legged horse in the Kentucky Derby. To do that well, you'd have to be an excellent jockey. At the same time, why not be in it to win it and ride a horse with four legs?"
"The fact of the matter is, the popularity of these bikes has nothing to do with the bikes themselves or the few people who actually have the chops to ride them with style. The fixed-gear is to 2006 what the Razor scooter was to 1996: a wheeled freak show for wannabes."