livery editor,
have the option to have convertibles or hardtops for your convertible cars,
customization like custom seats, wheels, and lights from real manufactures,
more world locations,
day/night, weather on all tracks,
bigger menu screen,
engine swaps,
drag races,
F1A,
more driver animations for example(showing the driver moving the emergency brakes),
better damaging system like airbags coming out on stock cars that support it, not being able to drive, lights destroyed, better paint scratches, windows broken,
Having a passenger drive with you for different license test,
online matchmaking,
free roam,
championship saves,
qualifications,
having replays similar to GT4
This is what I can see for the future of the GT series since it's the top sim in a console.