From GTPlanet Game Guides

Gran Turismo 5: Prologue was officially announced by Sony at E3 '07 by showing everyone a near two-minute long trailer. Another trailer shortly followed at the PlayStation Premiere event in Japan, showing off 16-player races as well as a cockpit camera view.

The game without question looks absolutely stunning - lighting, reflections, animation and detail are all shown in spades.

The rest of the screenshots can be found in our gallery section. Be sure to check them out!

Key Features:

• The first ever Gran Turismo title with online racing: drive online
  against up to 16 other Gran Turismo aces
• Race a total of over 40 stunning, high-performance cars
• Race on seriously realistic, real life tracks including the Eiger Nordwand,
  the London City Track and Suzuka - then race them in
  reverse and with alternative routes
• All-new physics engine means true next-generation vehicle handling
• All-new and improved opponent AI for a nail-biting race experience
• Access to Gran Turismo TV : a world of great motoring TV programming online
• Online Dealership: Access to car manufacturers online
• My Garage - a personalised homepage feature with friends,
  chat and personal game records
• Quick Tune facility allows you to adjust power, tyres, suspension and more
• All in stunning High Definition at 1080p
  (race: 1080p-60fps, replay: 1080p-30fps)

Release Dates

Gran Turismo 5: Prologue has been confirmed to have more than 40 cars and 5 tracks (including Daytona, Suzuka, London City Track, Fuji Speedway, and Eiger Nordwand), some with variations and reverse configurations. Full online capability has been confirmed, with 16-player online races and PlayStation Home integration. It is to be released on December 13th 2007 in Japan. Sony's expected date for Europe and Australia is March 5th 2008. If and when GT5 Prologue will be coming to the United States is currently unknown.

Gameplay

The gameplay in Prologue will be raced in one of two modes - "Standard" or "Professional".
Whilst online play will be conducted in an arcade-like racing mode. Gamers who use the Driving Force Pro and other wheels will be pleased to know that they are to be fully compatible with GT5 Prologue, and eventually Gran Turismo 5 itself.