Two-Face in Dark Knight

Well... for a while now we've heard about Harvey Dent becoming Two-Face in The Dark Knight. Now we're sure, since we saw in the third trailer, a photo of his burnt face is on youtube, and today a exclusive scene from the movie was released on Youtube. You can view it here.

If you go here, you can see two promo shots of Two-Face. Another leaked photo (as mentioned above) is of Harvey Dent as Two-Face lying in a Hospital bed. You can see that by clicking here.

So... originally, from what I remember, Two-Face wasn't even in the movie at all. At least I don't think so.... I recall Nolan saying that Batman 3 would begin with Joker's trial, and the Joker would throw acid at Harvey Dent, scarring him and forcing him to become Two-Face.

As for how this will happen in Dark Knight, I'm not sure. But I can tell you that Dent becoming Two-Face is caused by The Joker.