The demo has hit PSN everywhere, except the US store. Xbox Live will get the demo in September.
Official statement below:
Konami Digital Entertainment GmbH today releases the first of two free demos for the forthcoming PES 2012.
The demo is available free of charge* for PlayStation(R)3 via PlayStation(R)Network and for PC from http://dl.pes2012demo.konamionline.com/pes2012demo/PES2012DEMO.zip. The Xbox 360(R) demo will be released via Xbox LIVE Marketplace in September. This is due to unforeseen issues.
The demo is not representative of the final game, but KONAMI wanted to offer users the chance to experience the new gameplay advances, and Active AI and Off the Ball and Teammate Control systems as early as possible. A second demo based on the final, retail version of the game will follow in September.
*Users are responsible for Internet access fees.