In the DH trailer, when Voldemort holds Harry's face, (A.K.A. "Why do you live") Wouldn't his scar hurt?

I think that part is after Harry "died", so the piece of Voldemort's soul that caused the pain would be gone. Voldemort would be able to touch him without causing Harry pain.

It would also explain why he's holding him and asking, "Why do you live?" instead of killing him.

followup question. Y didnt Voldemort kill him then?

Oh it probably did, Harry just learned to keep that under control, didn't he? He had to be focused, Voldemort was holding his face, if he lost focus he would have been dead..

In the Goblet of Fire movie (and in the book) Harry's scar hurt when Voldemort touched him because the piece of Voldemort's soul that was embedded in it was trying to break free. However, now that that piece of soul has been done away with, Harry would no longer feel any pain there.

agreed with above
im so pumped

that part might be right after harry "died" in the forbidden forest and Voldemort is just confused and angered at the fact he's still alive:)