Yeah, for the Dreamcast, they use the term Gigadisc or something. It holds a Gigabyte of data, if you haven't already figured that out, and was thought to be very secure against pirating. Now, as you all may know, if a game doesn't take up an entire Gigabyte (which a lot don't), then you can succesfully burn them to a CD, and use that Utopia stuff to play them. It was an ingenious design at the beginning, but they didn't, and couldn't, forsee the ease of getting around it.
I look for future games to contain some kind of protection in the form of files listed to be way larger than normal, or something to that effect that will effectivly make the game data larger than 700MB so it won't all fit on a regular CD.