The Witcher 2 - Interview @ Gamasutra

CD Projekt Red Senior Producer Tomasz Gop chats with Gamasutra about their goals with The Witcher 2.  Tomasz emphasises they want to produce a "hardcore RPG", not an "action RPG" but explains the action combat is appropriate because of the subject.  Here's a snip on their tools and systems for creating non-linear gameplay:

Those kinds of systems have traditionally been what Western RPGs strive for. Can you talk about any of them in more depth?

TG: There are a lot of things, actually. You can see it even just in [this gameplay demonstration, featuring a combat encounter and branching dialogue]. There are systems that let us branch the story because we have more endings to this story than we had in The Witcher. Not one or two more; way more. We have a lot more factors that influence how the story branches and what you will see.

It's not only dialogue choices. For example, you want to take care of who you stick with throughout the game, your companions and so on. We also have companions in the battlefield. You don't command them directly, but they are independent guys or women who can help you, and they can change the outcome of a battle.

You have communities, societies. A lot of things are going on inside the cities, inside the places you will visit, and they're often independent of your actions. There are things that are going on that don't always wait for you to see them. Dialogue looks more lively. People can join in or join out of the dialogue. There's no limitation towards number of participants.