I've seen all the trailers and the new steering wheel for the game and it looks sick. Unlike the previous games in the GT series, this one will have a clutch pedal for the stick shift players and it will be more realistic with online features and capabilities. And over 50 life like cars.
YouTube - Gran Turismo 5 E3 '07 Trailer
YouTube - Gran Turismo 5 E3 '07 Trailer