OKAY. WARNING TO PEOPLE. IF YOU DON'T WANT TO KNOW HOW THE MOVIE DIFFERS FROM THE BOOK, DON'T KEEP READING!! IF YOU HAVEN'T EVEN READ THE BOOK, AND ARE JUST FANS OF THE MOVIE..I DONT THINK YOU WILL CARE :)
Okay, here's what they are changing...
In the final chapters of The Deathly Hallows, fans know that Severus Snape is killed at the Shrieking Shack by Voldemort's snake, Nagini. Though the iconic death is still a go, the location and tone of the scene have been dramatically changed.
Andrew Ackland-Snow, the art director for DH, reveals that the fall of Severus will happen at the Hogwart's Boathouse, rather than the Shack. You'll recall if you've read the book that the Boathouse is a crystal structure that sits on the lake near Hogwarts. The idea is to give a more "dramatic" and "romantic" feel to Severus' death.
And before you all get to booing because they've drastically changed something from the book, let me just add this: J.K. Rowling specifically signed off on this. In fact, according to Andrew, she "loved" the idea. I'm surprised by this, and I kind of wish nothing had to be changed. I understand why, but it doesn't make me happy.