Well, it's probably a bit narrow focussed compared to GT3, and given the size of the fields (knowing the series it will probably be 16 cars) it won't look quite as good, but previous instalments have had superb driving models and fantastic AI, so I think it will probably offer a superior racing experience.
Has there been any word on Logitech steering wheel compatibility - I would have thought it would have just about been compulsory for PS2 racing games now!