Every character that is engaging more audience and keeping the story as close to the script ain't gonna die for now because they have killed way too many characters they can't afford to kill anymore.
I believe Cersei Lannister gonna die because they have over used her just like Joffrey. Jon Snow gonna stay as they brought him back from death for some reason. And they are going to kill somebody famous but less important for keeping that element of surprise just like in all other older seasons. I think they are going to kill poor Arya this time.
Well, interesting, I appreciate your thoughts @kissofearth. I don't think any of the main characters will die this season, but some semi-popular characters like those I mentioned above. I will very surprised if Arya dies...maybe at the very end....anything could happen then, but not now. I do agree Cersei will die before it's over, probably by the hand of Jaime.