And if these patterns hold how can any social media service be the next big anything?
People just want a consistent interface to communicate. There's no UX reason to separate email, facebook, instachat twumblr or whatever from each other.
Yes there are different reasons for communicating but they can all function under one roof. The next big trend of sending pokes with 12 second color corrected videos that get deleted after watching can live inside Facebook, G+, or TwEmail 3.0