An interesting analysis of why the iPad is kicking other tablets to the ground is making a lot of sense to me. It also explains why we should not expect to see an iPad mini any time soon. I appreciate the potential of the smaller iPad, but it makes sense for Apple to be cautious.
The point was made by a writer that one big advantage that iOS has over Android is that it is optimized for just two screen sizes. Four if you count the different resolutions. This means that anyone writing a program for iOS just has to deal with those sizes. With Android, or any other open system, it can be displayed on any size or format. This need to be flexible is never going to allow the best graphics for all apps. When the iPad first came out, we had to deal with a number of iPhone apps X2 view. It never did look right.
This explains why a new iPhone with a larger screen has not been released. It also may mean that android has to deal with this issue to be competitive in the long run. I expect that an effort will be made to reduce the screen options, or a new way of sizing discovered.