I seem to recall that about 2 years ago Apple paid ~$400 million to another company that had a patent on the hierarchical menu system used by the iPod. Maybe after an experience like that Apple became afraid of the patent system.
This patent gives Apple the option to add these features to future products. It prevents another company from patenting the idea out from under them. And even if the patent office rejects the patent as not being novel (or non-obvious), that's OK too because it still prevents others from patenting features Apple would like to add to future iPhones.
