My coworker has been saying they are changing a lot from the books in this season. For example, he was saying that Jamie lost his hand in a completely different way, and that John climbed the Wall differently and a few other things. Honestly I don't really mind that the book and show have diverging stories, because if I ever did decide to pick up the books, it wouldn't be as if I was reading the same exact thing as I had watched. It doesn't bother me at all if the story changes, as long as it stays as good as it has been.
Spoiler
Yea the way John scaled the wall was different than in the books, but the way Jamie lost his hand was pretty close iirc. Some things they need to change because there are way too many characters to deal with in the show and since they cannot show a character's thoughts, they have to adapt a lot of scenes for the show to make sense. For example: in the books, Littlefinger never had that woman helping him in his affairs so she never got the chance to spy on him for Varys. Regardless, it certainly made for an interesting storyline, just like Podrick being amazing at sex and Theon's struggle being revealed to us a lot earlier than in the books are entertaining.
I have a pretty good idea what is going to happen to Gendry, I believe I put it in a spoiler up there somewhere. It is hard to discuss what is going on in this show when some people haven't read the books and others have.