I think that now that bigger screen iphones have been introduced and sales of ipad have been stagnating, it may help with the introduction of more innovative features and innovation of iOS. There is starting to become a need to further differentiate iOS devices and how they are used based somewhat on the size of the device.
I mean, why change what is working and selling so well? Now, were at the stage of, what if it's not working and selling as well? At least in regards to ipad.