They also skipped most of the part about Albus's sister and you are sort of left with a.."what happened to her?" feeling.
Another part I didn't like...(which actually the director hated as well) was the giants...they look kind of cheesy.
Finally a part that I actually loved that they changed a bit is when Harry, Ron and Hermione return from battle and find Tons, Remus, Fred, etc all dead. In the books I thought JK Rowling just killed people off randomly without giving enough emotion, or background into the killings so it was sort of like..."and he died, and she died, and he died, and she died"...and your like..WHAT???...and left with the feeling that she just killed them off for no friggin reason. I HATED that about the book (actually I didn't really like the last book at all). In the movie they really add emotion to the scene, and you get a real feeling that you have witnessed something horrific and it is just so sad. You aren't left with a "what the fuck?" feeling like the book, but more of an OMG feeling. It is sooo horrific and really makes the point about how bad Voldamort really is. It adds emotion where the books leave you sort of scratching your head.
The one thing I miss is at the very end when Harry and all are grown up (they aged them a bit..but they still look like children to me)....They don't mention Tonks and Remus's son. I was bummed about that.
Anyway, I loved it. We saw it in 3D Imax and it was great!