Some great speculation from Steve Cheney. He predicts Android platform and hardware specification fragmentation will become far more of a problem than any form factor differences, especially for cutting edge use cases.
It’s not even funny how bad fragmentation will hurt Android and Google in location based sharing and payments apps ... when your Android phone won’t communicate with others or at POS terminals (tablets / iPads) it will be tough to rationalize. [...] state of the art apps around local discovery / wireless will rarely support Android.
Certainly where I'm working now, we don't have a problem supporting multiple screen sizes on Android. Our fragmentation problems are caused primarily by vendors shipping Android with differing built in libraries, sometimes and surprisingly excluding ones that our application requires to function. This rings true for us:
The real trouble comes in different ways – e.g. a friend I know has been seeing a lifecycle bug crash the keyboards on ALL Samsung phones. It’s not an Android version issue, it crashes the app across revs; it’s something non-standard Samsung is doing to Android itself.