Writing at Fast Company, Farhad Manjoo sees a big battle involving Apple, Google, Facebook, and Amazon in the coming year:
The four American companies that have come to define 21st-century information technology and entertainment are on the verge of war. Over the next two years, Amazon, Apple, Facebook, and Google will increasingly collide in the markets for mobile phones and tablets, mobile apps, social networking, and more. This competition will be intense.
It is interesting that Microsoft is missing from the list of combatants.
The article is substantial and I found it worth a read.