Mild spoilers and very little OMG THAT PART-ing--I won't be cruel:
1. Dakota Blue Richards is fantastic. In my own opinion, she is utterly perfect, although I'm sure 100% of everyone has never agreed on anything. But that is my opinion. Watch, in particular, when she offers to be Iofur/Ragnar's daemon. It's weirdly, creepily seductive... just like Mrs. Coulter.
2. There's a number of trips to the Department of Backstory, but in order to reach people who haven't read the books (yet), you have to have those moments--they're not for us book fans; they're for viewers like my mother, who didn't even realize there would be small animals in the movie. Given that you have to have those moments, they're integrated about as well as I've ever seen.
3. McKellen!Iorek isn't so bad; he sounds bearier in most parts than he does in the trailer. I'm still a little heartbroken that we got to hear Nonzo Anozie in the first two trailers only to have him taken away, though.
4. Tony Makarios' role has now been given over to Billy Costa, which I was hoping they'd do, because it's a perfect example of character economy--use someone Lyra already knows for a brief but pivotal scene, kind of in the Arwen/Glorfindel mold. Which is to say, yes, they include the Tony Makarios scene.
5. There's a MAJOR plot switchup--the movie had been so faithful up until that point that I actually panicked, and then I realized what they were doing: putting the panserbjørne showdown before Bolvangar. The way it works out, it makes sense--Svalbard is a great scene, but it's less epic than the battle at Bolvangar, and the rhythm of filmmaking tends to require that you save the biggest for last. Actually, that final scene with Lord Asriel would have been a fantastic way to end the movie and keep those two sequences in their proper order, but as Chris Weitz noted several weeks ago, they had to move those three chapters to the second movie in order to make the first movie feel like a complete story with closure. Without the big Lord Asriel sequence, the rhythm of the story does seem to work better with Bolvangar second. What I'm saying is, when you get there, don't panic. Other than Lyra voluntarily showing up at Bolvangar, which is a major moment of departure (it's pretty much the biggest departure that I can recall. If that's all we have to complain about, they did a pretty good job), they do a fairly good job of staying faithful.
6. The film moves. We got up to the part where Lyra runs away and I was like, "Wow, they did all that in ten minutes?" and I checked my watch and it was seven-forty. It's funny--everything's there, it's just streamlined. Occasionally things are changed a teensy bit to make the streamlining logical, but I really can't think of anything that I just desperately wanted to be in the movie that wasn't there. And there were a number of things that did stay in that surprised me. But I won't get into that...
7. Random Point in the Movie Where Cleo Tears Up for No Good Reason: When the witches arrive at Bolvangar. I have no idea why.
Warning: If people ask me questions in the comments, I will answer them. Do not venture down there unless you're willing to risk being spoiled further.