According to Siliconera (linked above), a God of War III PS3 demo will be available from the Japanese PSN store on November 19, 2009.
This comes as part of a promotion for the Japanese version of Infamous, and codes will be issued which can be redeemed from November 19th through February, 2010.
To quote: "As a promotion for the Japanese version of Infamous, Sony is giving out codes to download a God of War III Japanese demo from the PlayStation Store.
The demo will be available on November 19, about a month after Infamous' October 15 release date in Japan.
Codes can be redeemed from November 19 to February 2010."
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