We've seen that going on in fandom for quite a while, since fandom is itself a mix of subcultures. It started with SF fans, of course, way back in the 1930s, but ever since then other folks with related interests (horror fans, fans of particular TV series, etc.) have taken to showing up at SF conventions or organizing their own get-togethers where they can sit around/stand around and geek out about the things that excite them. The Internet has only accelerated the process by making it easier for people in widely-separated parts of the world to communicate with each other.
So are fans on the cutting edge of this phenomenon? Or is fandom just the part of this cultural shift most visible to me because I'm most familiar with it?