I just noticed yesterday that there seems to be a pattern of certain trends or even fads among OSR writers and commenters over the years. OSR as it exists today is usually considered to have started with OSRIC in 2006, but really appeared to be a thing that gets discussed on the internet around 2008 or so. Look at any of the oldest websites that are still around and almost none of them is older than that.
And as far as I am able to tell, there have been four main periods so far: Retroclones, Megadungeons, Sandboxes, and Weird Fantasy. Though I am getting the feeling that Weird Fantasy might already be on its final legs. But I am wondering what the next big thing that gets everyone excited might be. I think one good candidate might be Campaign Settings. The most highly praised releases of the last couple of months seem to be Yoon-Suin and A Red and Pleasant Land. Wouldn’t be surprised if we’re going to see more people hopping up on that train, though it might not be lending itself to discussing the theories behind it as much as the previous trends.