I would like to speculate a bit about the future of mobile phones and take an educated guess on what is going to happen.
Up to June last year, mobile phones were closed platforms. You had to have the permission of both the network operators and the phone manufacturers to develop an application. Then, you had to go through the network operators to distribute that application. A long process that only large companies could afford to go through. On June 29, 2007, when Apple introduced the iPhone, everything changed. Small independent developers were not only given the opportunity to develop applications for the iPhone but were given distribution independently of the network operators.
Let's speculate about what is going to happen. After being exposed to the iPhone, I believe that consumers are going to require from their network operators to get phones that offers the same features, including the same diversity of applications. Pretty obvious, isn't it? The problem is that, because of the differences between phones, you have to develop a specific version of your applications for every different phone. If you want to provide broad support, you have to produce hundreds of versions of your application. Small independent developers can't afford to do that.
So, here is my guess: To solve that problem, network operators are going to require from phone manufacturers unified, open platforms. And the only way that phone manufacturers can achieve that will be through 3rd party operating systems. I believe that in the next two years, every mobile phone except maybe the very low end models, will be running one of following operating system: Windows CE, Android or MacOS (The iPhone runs a cut down version of MacOS).
Now, what is going to be very interesting is to see what network operators are going to try not to be transformed in dumb pipes and keep their control on the content market.