[loire280]

Another thing to worry about is manufacturers abandoning support for old phones prematurely, or causing long delays between updates to new major versions. (I'm not sure if Android phones can update over the air, but if not then you may have a large number of users who never upgrade their OS.)

Yes, technical users can probably acquire third-party firmware if the manufacturers drop the ball, but that's not a mainstream fix.

Android will not be fun to develop for if you're targeting (hardware spec fragmentation) x (Android feature fragmentation) different combinations of phone.

[DrSprout]

Well, the iPhone solution is basically throw away your phone every 18 months, which should work equally well on Android.

[loire280]

The carrier subsidy model provides an incentive to throw away your phone every 2 years, anyway.