The Witcher 2: Assassins of Kings is supposed to be released early next year, and if you still have your old The Witcher save file lying around then do keep it until then - according to an employee at CD Projek you will be able to import it into The Witcher 2. Just like in other games that comes with this feature, importing your save file will have an effect on how certain characters react to you and how some events play out.
That's always a great feature in roleplaying games. Time to dig up that Witcher box from the pile of PC games and give it another go, me thinks...