There was also one new character introduced today, and his name is Darth Sion. As you can probably guess by the "Darth" in his name, he's a bad guy, and he's a bit like Darth Malak, in that you battle him a few times over the course of the game. Darth Sion is definitely a candidate for "nastiest looking Star Wars character", as he's basically a rotting corpse that is being held together by the power of the Dark Side.

The character model is very detailed so far, with mottled, cracked grey skin, lots of rotting holes in his flesh, and one disgustingly milky eye. According to the producer, Darth Sion does not fear death, as death would be a blessing to him. It will be interesting to see why Darth Sion is being kept alive at all. I'd say that there's a good chance that it will be for some insidious reason known only to the Siths (and the insidious developers at Obsidian).