I think scenes at Grimmuald Place will only be severely cut from the 5th film only because it was more running around the house of Black and it was pretty much Harry's summer. They won't cut Umbridge since she is important later on. Dan has said on TRL, that there is a kiss in the next film. I have no idea if they will actually cut the Harry kissing Cho scene. The piensive scene won't be cut since we see Snape's past a bit and they might shorten scenes in the Department of Mysteries. But definitely Dumbledore facing Voldemort will be there. I really look forward to how they work the ending because the ending had alot of action.