updated 04:10 pm EDT, Fri September 30, 2011
iPhone 5 Assistant given leak-based demo
The iPhone 5's Siri-based Assistant feature has been supported by separate, follow-up tips. Going so far as to contract out a concept video (below), MacRumors understands that the advanced voice command system can be invoked from nearly anywhere by a long press of the home button. From there, owners speak a natural language command for messages, searches, and other tasks, the results of which get put into a "conversation" which shows all the details.
Much like Voice Control, certain commands may need follow-ups, such as which phone number is the target for a text message. Wolfram Alpha may even play a role by using just a small piece of information to extract more.
The system ties into Nuance-based voice recognition and, importantly, should have "great accuracy." Google already has Voice Actions in Android but usually relies on them for direct actions and is using its own engine. Siri drew Apple's notice primarily as it let users string together complex actions, such as creating an appointment, by using logically constructed sentences.
Apple is believed to be keeping the feature as exclusive to the new iPhone, whatever its design may be. Whether that's due to hardware requirements or just to drive sales isn't apparent. Siri as an app could run on older iPhones but was also confined to one app, not the entire OS.