A phone you can talk to that understands what you're saying? At a basic level, Apple's had that since the first version of Voice Control was introduced with the iPhone 3GS. The only problem is that it's been pretty limited, working only to make phone calls to people in a contact list and begin playing a song or playlist.
Reports from TechCrunch
earlier this year claimed Apple was working on a partnership with Nuance
that would build far more advanced voice technologies into iOS 5, and presumably some extras for the next iPhone. Yet when iOS 5 debuted in June, the voice features were nowhere to be found.
More recently, reports from 9to5Mac
posted screenshots of a microphone icon sitting in the iOS software keyboard, while suggesting that the feature will let users launch apps and navigate around the phone with their voice. Outcome: TRUE
Apple announced Siri, named after the voice technology company Apple acquired last year. The feature lets users speak commands to their phones and see the results without leaving whatever app they're on. You can read more about it here