I think the future of reddit, if it doesn't fix its UX problems, is not being usurped like Digg, but being chewed up by piranhas like Craigslist. There probably

I think the future of reddit, if it doesn't fix its UX problems, is not being usurped like Digg, but being chewed up by piranhas like Craigslist. There probably won't be a multidisciplinary full-on reddit "replacement", but a bunch of sites that manage to steal large fractions of the userbase. The "long tail" can't spin off a new site for every subreddit, but it can split into several smaller tails. StackExchange is the first and best example. Two categories that seem like they could be targeted by insurgents are games and localities. A lot of subreddits for certain cities and/or certain games are good, but it's an open secret that some games and/or places have absolutely terrible subreddits -- and reddit doesn't have much of a correction mechanism for that, save for the userbase getting fed up and establishing a new one (like when the creator of /r/marijuana started posting a bunch of racist drivel and everyone moved to /r/trees). The big thing protecting reddit right now, IMO, is that /r/worldnews for all its faults is still a much less awful way to browse international news headlines than the vast majority of news sites. Sure, the headlines are editorialized and the comments are mostly trolls, but at least it won't crash your phone browser and it's not gonna interrupt your unhealthy obsession with foreign affairs to bring you someone else's unhealthy obsession with celebrity gossip. And for all the ads pimping the reddit app, just try to download a recipe from Cookstr or the Food Network or whatever and you'll soon be begging to see fake loading screens that ask you to download an iPhone app. (Serious Eats is good though.) So it'll be a while.