It depends on what criteria is used to judge greatness of course. By my evaluation, the iPhone's notifications and multitasking UI have been horrible since day one. That hasn't stopped Apple from oveloading push and local notifications with third-party multitasking, all without much change to the fundamental problems, making the experience worse over time. Marco's focus on the simple and shiny, at the expense of the functional and robust, indicates that we have different standards for greatness.