I think the major mobile operating systems are rapidly approaching maturity. I don't expect any radical changes in Android, iOS or WP at this point. iOS in particular hardly looks different than what Steve demoed in 2007.
This is also why I think Android's upgrade problem may not turn out to be so important in practice. Even if the carriers utterly fail to roll out OS upgrades, the 2-3 year device churn cycle will eventually get new versions in play and ICS has fixed most of the glaring problems with the OS and is "good enough". Once Google makes major components like the browser upgradable as apps it won't be that important to rev the base OS.
This is also why I think Android's upgrade problem may not turn out to be so important in practice. Even if the carriers utterly fail to roll out OS upgrades, the 2-3 year device churn cycle will eventually get new versions in play and ICS has fixed most of the glaring problems with the OS and is "good enough". Once Google makes major components like the browser upgradable as apps it won't be that important to rev the base OS.