From what I've seen from my friends that use facebook, the majority of them have for the most part stopped using it or just don't update, browse as much as they use to.
I doubt FB remains relevant over the next 5 years. Twitter seems to have replaced it for a lot of individuals.
The majority of my friends in their mid to late-twenties use Twitter far more than Facebook at this point, though even their Twitter usage seems to have waned a bit lately. As more and more sites are starting to crop up that have a more focused social element, it takes away from Facebook's or Twitter's or anyone's ability to dominate the sphere. A lot of people used to spend their social networking time entirely on Facebook, than it seemed to split off with Twitter, and lately a lot of people spend more time on Pinterest than Facebook and Twitter combined. This continual splitting-off and interest-focused evolution isn't going to slow down, it's only going to accelerate. Even if Facebook fixes some of their core problems, it won't change the rollout of other options that are more appealing to specific groups of people.
Ultimately, we're moving away from being a mainstream-oriented world and moving towards a niche-oriented world. Perhaps much of Facebook's success is that they rose to prominence in the social networking world before the concept of mainstream was killed off by the internet, and before texting was ubiquitous. They were ahead of the curve when people still seemed to function as if "bigger was better," whereas now, whatever we as individuals are most interested in is better, and the sampling of people interested in that is much smaller. But the internet allows us to connect and revel in our little niche markets. We don't need mainstream, because mainstream was overpopulated and unfocused and resolved to lowest common denominator content far more often than not. We don't need Facebook to feel connected, and if anything, it just makes us feel all the more disconnected when we have so many "Facebook friends" that we simply do not care about at all.
If I want to talk about Apple products, I can come here. If I want to talk about hockey, I can go to any one of the message boards focused on my favorite team. If I want to talk about guitars, or Thai food, or New York City, or wherever, I'm not going to go to Facebook. Why would I? Facebook boils down to vanity at this point, not true communication. If people want to communicate, and I mean really communicate, they're not doing it on Facebook. Most people are posting useless drivel on Facebook; sharing whatever moment they deem worthy to essentially announce, "look at me!" There's a market for that, to be sure, and those are the people that still use Facebook a lot. Coincidently, they're also the people that get tend to get trashed the most in real life. And what cracks me up is how many times I've heard something like, "It's not like they are so annoying in real life, but all the crap they post on Facebook ALL THE TIME just makes me think they may be the most horrible person ever!"
This is all Facebook's real problem, and so far they've addressed it by turning every "like" into a page or category and lumping you together on a page you'll never look at with people who also "liked" something. That's not going to inspire communication or foster community. You can't just invent it with pages spawned from metadata in a spreadsheet. It's just too easy anymore to find real communities online, started by people passionate about a topic, and driven by people passionate about a topic.
Eh, I'll admit fully that I've become more cynical about Facebook, but the more I think about it and try to be objective, the harder I find it to believe that Facebook will continue to be relevant in the future. Five years might be generous. After all, look how fast Myspace died.
