In a new support document entitled “iPod shuffle (3rd generation): About headphone compatibility,” Apple has disclosed that the new iPod shuffle can be set to play audio, without additional user input, even without the earphone-based controls.
“When a standard headphone or audio accessory is connected you can initiate audio playback by simply switching iPod shuffle to the play in order or shuffle position from the off position… iPod shuffle will resume playback of the content that was previously being played at a fixed volume level that cannot be adjusted from the iPod itself.
If iPod shuffle is connected to external speakers or a car stereo, volume adjustment may be possible from those devices.” While track control will still be impossible, this method should provide a temporary solution for owners who want to use the device with their car stereo or external speakers, until a proper adapter is available.