Really shocked by the Bran news, and as of right now I'm more apt to believe that Hodor isn't in the season, but Bran is; we're basing all of his off the actor who plays Hodor saying he's not in this season. It doesn't make sense: why wouldn't they just film some made up shit, or delve into TWOW spoilers but avoid major stuff (I'm pretty sure Bran's chapters will reveal Jon's parentage in TWOW).
Not buying that Aegon isn't in the season either. It would make sense for them to avoid discussing him considering it would be a massive spoiler for show watchers to learn a (alleged) new Targaryen will show up. Similarly they kept secrecy all around the Ramsay Snow role in S3, going so far as to name him "Boy" in casting calls and the scripts. I'd imagine something similar is happening with Aegon.
One concrete thing we know: Mace Tyrell (replacing the role of Harys Syft in the book) is going to Braavos to treat with the Iron Bank. Meryn Trant is coming along with him which is interesting, as it could mean they'll
TWOW preview chapter spoiler:spoiler (click to show/hide)
film the Mercy chapter, and have Arya kill Trant (since Raff The Sweetling isn't in the show).