AppleTV then asked me to enter my Apple ID and password, which I did. The downloads started immediately and continued overnight. This morning I checked and the screen announced "Marco Polo ready to watch". The other four shows were also downloaded.
Next I connected my iPod to my PowerBook and synchronized the purchased shows to the dedicated iTunes hard drive. I also copied the files onto my iPod. The Apple Extreme moved the data at around 2.6MB/sec which is impressive! Here is a screen shot of the synchronization:
So, another step along the road to completely understanding what AppleTV can do. There is some trial and error in all this because other than the Apple video I have not found any reference manuals for take 2. The software is intuitive but I have to think that I am missing something along the way!