They are definitely changing alot. They have to because David Yates has already over-stepped his boundries and has already included stuff from here in previous movies. For example, we just saw the death eaters flying in HP6, so the whole scene with the 7 Harrys is out. This is probably why they are shooting the Harry and Hagrid scenes on the streets - because the death eaters can no longer be on brooms (we already know that they can all fly!). Now they are adding scenes with Scrimgeour. There is going to have to be more cuts if they are going to add things as well.