Well, to be honest, I don't think anyone outside of certain tech-giants' walls can accurately answer that, and even then, they will miss the mark (aka Google+).
However, we can take into account where things were and what the current state of social media is right now to attempt accurate predictions. We call that "forecasting". I know, it is crazy talk.
The question often spins to an idea that I have some secret knowledge about a fledgling social channel that we all need to know about and move to.
This is one of the hardest things to predict, simply because of the strangle hold Google, Facebook, Yahoo, Twitter and LinkedIn have on the current state of social media in the world. And the thing is, they aren't going to give up their monstrous size to some little start-up.
Think about this way, the hottest-fastest rising social channels that haven't been bought up by Google/Facebook/Twitter/Yahoo are what? SnapChat is about it, currently. Other popular startups are based around generating a product or service (a la Uber) and not about being a true social network. Even then, the giants are buying up things they think they can tap social into (think Facebook buying Oculus Rift).
This leaves little room for channels to grow at a rate to beat the top dogs (referencing Ello here). Also, new channels have to offer something other outlets already don't do or they need to do it better. And if they do it better, you best be sure they will be offered a crap load of cash to give it up.
Social and Search Ads Will Be Huge.
If you haven't generated a strategy for buying social advertisements, well better get to it.
This also means you will need actually create a budget for your social strategy, outside of paying someone to actual run your social media channels.
No One Is Walking Away From Facebook...Yet.
Studies and posts show how Millennials (and others) don't use Facebook (They do), and people continue to feel disenfranchised by the management of the social network. However, Facebook is still the largest network by far (With more than 1.2 billion users, you have to subtract almost 700-800 million users to get to the next highest count of active users for a social channel).
Even if Ello, or other outlets like it, take away users, Facebook isn't going to slow down. With its sights set on China and other Asian markets, Facebook will continue to dominate the social media world.
For now, of course.
Mobile. Mobile. Mobile.
If you haven't developed a mobile strategy for everything you do, you need to. Seriously, this almost isn't a "prediction" as it is solidifying recent years of reality.
Mobile ads and mobile design need to be in the forefront of your mind with any project. Yes, ever real-world advertisements need to have mobile in mind (i.e. How can we get people to stop looking down at their phones? How do we make our outdoor ad shareable?)
Mobile is here to stay, and mobile marketing shouldn't be an afterthought.
Do You Stream? You Should.
With Amazon buying up Twitch, CBS and HBO distributing content through streaming, 2015 will be the year of streaming. Streaming will grow and it will hopefully be the year of actually streaming live events (no green room cameras or backstage cameras).
And for social that is huge. The reason cord cutting is getting so huge is because the massive influence social media has had on how we consume our content.
Putting content online in this manner means a higher opportunity for users to share ideas, content and comments about that live stream.
This, of course, allows these streaming services to promote more effectively online (What do you think works better, "Watch this program at 8 p.m. EST," or "Watch it right NOW!").
The next year is going to bring about a lot of change. However, new technologies, programs and applications are being created daily, and making accurate predictions is a very hard thing to do anymore.
So, be fluid, read up and make sure your strategies and goals take into account how you can properly utilize social networks to meet your business goals. Do that, and you will have a great 2015, no matter what Google, Facebook, Yahoo, Twitter, LinkedIn or any of the hundreds of social channels, networks and apps do.