The $29 US Apple Stereo Headset, included with the iPhone, works as a microphone on the new MacBooks, according to TUAW.
While this might not be a top-line selling point for the laptops, it's actually a very nice added feature for users of VoIP software (Skype, Gizmo) or iChat audio conferencing. Trimming your laptop bag by skipping the USB headset (or the Bluetooth headset, for that matter) will save wear and tear on your back; not having to buy another device to do sound input for your laptop will save wear and tear on your wallet.
While this might not be a top-line selling point for the laptops, it's actually a very nice added feature for users of VoIP software (Skype, Gizmo) or iChat audio conferencing. Trimming your laptop bag by skipping the USB headset (or the Bluetooth headset, for that matter) will save wear and tear on your back; not having to buy another device to do sound input for your laptop will save wear and tear on your wallet.