Sony showed off a work-in-progress version of Gran Turismo 5 Prologue for the PlayStation 3. The near-final version of the game didn't differ much from the preview version we recently saw, but the press event gave Sony reps a chance to reveal some updates to the game. In particular, they explained the differences between the game that will ship to stores on a Blu-ray disc and the version that will show up on the PlayStation Network store.