I cant say for sure but im sure they would have to, cos so many people would be angry if they left it out. Also people who havent read the books would need to know what happens, especially cos its the end.
Most likely, since they're trying to make the last two pelikula (Deathly Hallows is going to be split into two pelikula - for those who didn't know...) the best out of all of the other six.