Mobile market is growing quickly. This allows for  some space every for a new player to come and play the game of mobile OSes. In a rapidly changing market, we've passed from a strong Apple dominance (4 years ago) to an Apple-Android market split, where Windows Phone 7, Symbian OS and others fight for a share of the pie. What will we have in 4 years? It is hard to tell, but new systems are always welcome. Wether they'll remain or disappear, only time will tell. The new contestant? Fusion Garage's Grid OS