Based on the iPad release (no camera), I doubt we will see a camera in the Touch until the exclusive agreement with AT+T expires. Apple makes too much money in subsidies from AT+T to risk cannibalizing iPhone sales. I originally thought they might put a camera in the Touch sometime this fall but now I think that there will be no camera in the Touch for a long long time.
If you want an iPod Touch and can live without a camera, you might as well buy one now.