It was a strangely quiet film. Even during the battle at the end it was very quiet. And it sounds like they trimmed the "surprise, he isn't dead" scene. I mean, one minute he was dead, the next minute, there was the sound of zipping and zapping and then I heard him talking to Hermione and Ron, as if, "oh, no big deal". It was weird.
I'm not sure they mentioned the Hufflepuff cup specifically. They did go into Bellatrix's vault to retrieve it but I don't remember hearing them actually discuss what it was. The others followed true to the book though (even with "I am ready to die" revealing the Resurrection Stone in the Snitch).
It did sound like Neville got to make a nice impassioned speech to Voldemort and pull out the sword, but then I heard Harry say something like, "We have to get the snake," so I don't think Nagini was killed at that spot.
They did indeed allude to it being King's Cross. They even had the little monstrous piece of Voldemort there, with Dumbledore's line about "we can't help" or something. Seemed pretty close to the book.
One thing they did move; they took the whole exposition about the Elder Wand and its true master OUT of the final fight between Harry and Voldemort, which seemed to be fought rather silently (i.e. sound effects only, no dialogue). They pretty much summed it up instead in a little Harry/Ron/Hermione discussion post-victory. Not really sure why they did that. Maybe they wanted to make Harry seem more "powerful" (answering some of the criticism of him being too wimpy). They also seemed to remove the rebuilding of Harry's wand (at least I didn't hear any "reparo" in there) and it sounded like they had Harry break the Elder Wand in two (which I kind of liked, because I never liked the idea of him just putting it back in Dumbledore's coffin for any wannabe-evildoer to get again). And they did have the final scene with the children, which is nice.
I'm not sure what it actually looks like. Just by listening, it seemed a tad unsatisfactory albeit a nice wrap-up of the series. I think most people will like it, but to me it "sounded" a bit empty... basically, it "sounded" like the second half of a movie. Still not sure they couldn't have just made one big-ass 3-hour film and not split it up into two but we all know that was a cash grab.