The edited video is "exported" out to the camera over the FireWire connection.
That's how I watch my high definition video on my Panasonic plasma HDTV (using the HC1 as the playback device (connected with component cables to the video-in - and the stereo audio out from the camera to the TV's audio-in).
It will be up to your video application's output capabilities...
I know for other digital video cameras, you can transfer videos from the computer back onto the video camera. Is it possible to transfer videos from the computer back onto a Hi-def digital camera (the Canon HDV 1080i)? If so, how? Thank you very much!