A radio station in Atlanta just had a contest on this very question this evening. Atari means "you win" in Japanese kanji.
http://www.rygar.info/rumor.htm
http://www.sakuraarchives.com/faqs/lipsguide_kohran.txt
If that last link doesn't load, try the Google cached version:
http://216.239.53.100/search?q=cache:W6LVC6qgcP0C:www.sakuraarchives.com/faqs/lipsguide_kohran.txt+atari+meaning+japanese+%22you+win%22&hl=en&ie=UTF-8