Ars points out that the new iPhone OS has some special speech-related references with a codename Jibbler. It looks to provide voice synthesis and also rudimentary voice recognition for functions like voice calling and possibly more advance featres like voice navigation of Springboard, the Finder of the iPhone.
Our sources turned up references to classes and methods named VSSpeechSynthesizer, VSRecognitionSession, SBVoiceControlDisableHandlerActions, SBSensitiveJibblerEnabled, and SBVoiceControlSoundCompletion. SB refers to SpringBoard, and VS likely refers to Voice Services. The separate Voice Services classes leave open the possibility that Apple may eventually allow access to these services via the official SDK. There’s no indication whether these voice features will be tied to newer hardware expected this summer or if the features will be compatible with existing iPhone hardware.
Finally, these functions could help out with assisted services for disabled users and help in their ability to interact with the iPhone and the iPod touch.
Apps like Google Mobile and Vlingo have used voice recognition on the iPhone but the means to do so has never been built into the Core OS..until now.