I read this information on Wired's Gadget Lab and thought I'd share it with my readers.
It seems that there are rumors that Apple will announce a new type of mapping app at its World Wide Developers Conference on June 11. The buzz around that announcement is because it is rumored that Apple will be leaving Google Maps and using its own map database. With the huge number of iPhones out there, this could potentially be a problem for Google if suddenly all of those "map hits" are going somewhere else.
So… the thinking goes, that even though Google has a developers conference of its own coming up (called Google I/O), this announcement is more of a pre-emptive move to show & detail why Google feels it still has the best mapping available. By showing improvements and perhaps something new, radical, and different, Google may be hoping to get the word out on changes and improvements before the public starts discussing Apple's new mapping capabilities.
Of course, all of this is purely speculation. However, the timing of the event is definitely, if nothing else, interesting.