If you feel Apple event today is a letdown, at least you should enjoy Siri personal assistance feature, which delivers a truly revolutionary in phone usage. The features only works on the iPhone 4 and iPhone 4S.
Apple acquired Siri last year, just after about 2 months after the Siri app went online in Apple App Store. The artificial Intelligent engine built-in Siri allows the phone to launch various services with natural language.
Just push and hold the home button and start asking questions as you ask to a concierge service, chances are the phone will understand your question and provides the answer. In addition, Siri can read back or help you to dictate text messages.
Take a look at the below demo for more! (it is still unclear whether the voice can be switched)