It's set to be a pretty wordy game with Obsidian saying it has over 600,000 words in it and that they are aiming for something that can be replayed multiple times.
“We designed the game to be one you can play multiple times. At the bare minimum, there are four major storylines through the game, but within each of those storylines, there's a lot of different permutations and variabilities,” game director Brian Heins explains during the demo. “One of our major questlines, there are actually eight different possible playthroughs of that major questline, just based on different choices you make in different areas of the game.”
Should be quite interesting to play someone who is ostensibly a bad guy.