I think that perhaps Pettigrew is the one getting the reprieve.
As for who dies. . .I think Ron, definitely. Maybe Petunia? Hagrid? Not sure.
But I think there are going to be more than 2 main characters that die, because the news articles all say that Rowling is going to kill off two more characters than she intended. . . .and I'm pretty sure she was already planning on killing a couple of people..

I think it's cool that she's pretty much done with the 7th book. I don't think that releasing the book so close to the release of the 5th movie is such a good idea, though.
I almost wish that she'd wait until the 6th movie was out before publishing the 7th book, lol.