If there is one thing that mobile operating system developers and hardware manufacturers crave above all, it is being able to create a new familiarity.
Think about the smartphone you use today and how familiar you are with it. You can probably check your email, your calendar, catch up on Twitter and surf the web while waiting to be served at the coffee shop and not even think about what you are doing. This familiarity grows on you and your smartphone very quickly becomes an assistant that you cannot live without.
Now think about moving to a new platform and what that entails. New apps, new ways of working, new hardware to understand and a completely different experience. Hardware manufacturers tend to be hamstrung to a platform, but the goal of Microsoft, Google, RIM and Apple is to make their offerings compelling enough to make you want to change.
If I had to guess, I would say that 60% of people are happy to swap because they do not use enough features anyway, 20% are commited to their current platform, but would swap if something compelling enough popped up and the final 20% are stuck for many years with the platform of their choice.
Creating a new familiarity is probably the hardest job of all for the big players in the mobile industry.