When I long-press the Home button on the iPhone 4, I get a blue screen that says "Voice Control" on the top. However, most of my commands, including "FaceTime" and "Photos," do not do anything. Usually, the iPhone returns the message "No match found."
I was able to get it to play a song by saying "Play," but it did not recognize "Play Next" or "Cancel." It did however recognize the command "What is this song called" while the song was playing.