As quoted from the article over at GTPlanet.net ~
"If you're in France, head on over to the Paris Game Festival for your chance to play on the Gran Turismo 5 build that we saw running at GamesCom last month. The show is open to the public September 18-20. Rumors are coming in fast, however, that Sony representatives on the show floor are confirming GT5's release date will be announced next week at the Tokyo Game Show, and the playable demo there will feature the Ferrari Enzo."