That is really interesting.
http://www.transitive.com/news_quicktransit.htm
It could save a company money by making one version of a game and including the emulator software, depending on the cost of the emulator. But then again, most game companies are only making Windows games, so it would only appeal to Mac and *nix users and Windowers that like Mac and *nix games. At least that might save Linux games from the almighty power of rm-rf. (Format command)