According to this Wired article Apple will possibly be releasing a iPod Touch that will have a built-in camera and a microphone. Based on the article it seems to be a very high chance that they will be releasing it. I think that with the iPod Touch having these capabilities Apple will really broaden their customer base and you will then have many more possibilities with just an iPod Touch.
http://www.wired.com/epicenter/2009/07/apple-preparing-ipod-touch-with-camera-microphone-source/