The Witcher 2: Assassins of Kings is still primed for more downloadable content, and PC players will get it for free according to CD Project RED development director Adam Badowski. If you're waiting to pick up the impending Xbox 360 port, though, you'll probably have to pay up for any future DLC.
"All DLC for the PC version is and will remain free," Badowski told Rock Paper Shotgun. "That's not likely to be the story for the Xbox version, because of certain Microsoft policies that need to be followed. But on PC, once you buy our game, you don't need to worry about any additional costs – we will provide all updates, including those featuring new content, for free."
He does point out, though, that a full expansion pack would warrant a paid release, if they choose to make one. "But this is a purely theoretical discussion at this point, as we have yet to confirm or even plan any official expansion packs."
Offering reasoning for the decision, Badowski says they "don't like to see gamers treated like dairy cows that are primed for milking," as DLC is often planned as an additional source of revenue. He says CD Project RED is currently focusing on the updated version of the game, and early next year that focus will shift to the Xbox 360 "adaptation."