While share is the big part of mobile, there is a long way to go for any companies in the market. First I can think of is that, share should be based on receivers, not containers, when you share something, it really doesn't matter what you use to share, it matters only who you want to share with.when I share a video to you, no matter use twitter, weibo, email or facebook, the only thing, only thing you care is who will watch it.
my first prediction is the world would become more people centric, and clearly no company has done enough so far. second, picture sharing services would be, if not already, the hit of next round, and I incline to believe google's this service would grow very fast, with the help of its database, maybe a year or two will second the market after facebook. Just predictions, the main concern is, is facebook fast enough to kill google by using it social things to build its network, or google react quickly enough to transform its somewhat old mega database to something valuable to challenge facebook dominant role in the market.