I think this movie is very good... the best Barbie modern movie...
It has a very good plot, also the characters are well done, I must say that I imagined Dame Devin as a bad villain, but it turned out I was wrong about it, 'cause she was quite good... And of course, she "killed" someone, so this is something that adds some points to her...
I would give this movie 5 stars, in fact, 'cause after 3M, I think any movie could be compared to it, except this...
Something about characters:
Blair: I liked her very much, her flaws make her seem more natural, she's not perfect and I think this also adds some positive notes to the movie itself
Hadley, Isla and Delancy: I liked them all, they were very well done, even if I'd like Hadley more if she was different in the movie... I don't really like her hairstyle...
The change of heart of Delancy was very good, I think changing for being sorry for someone's fate (Blair and her family's one) is a very emotional thing... I also liked how she was avoiding her coronation and then she put the crown on Blair's head...
The sprites: I liked very much Grace, she's funny, also her voice isn't really bad, but I thought Caprice would be prettier... Harmony... well, in fact, the only one that spoke in the movie was Grace... I wanted to hear Caprice and Harmony as well, but... it's okay, BTW...
Prince Nicholas: I wanted him to be in more than just 2 scenes! This is what I didn't like, but his voice was very good and also he looked good... and he was kinda funny...
Miss Privet: One of the best Barbie characters ever! She was... special, she's probably one of the reasons of why I liked this movie so much... her voice, her behaviour, the way she didn't really stand Dame Devin...
The other characters (Portia, Miranda, Lorraine, Josette, Wickellia, Emily, Blair's mom etc.): They were very good background characters, also they had good names... but I still don't understand why they has those names but they gave to the main characters some names that were already used in other movies...

Well, this was my review...

I agree with many of your points. It is definitely the best modern BM. Haven't seen one this good since 3M. The villain was actually a murderer, not just some spoiled brat. I also wish Prince Nicholas was in more than just 2 lousy scenes! And the names were very creative, not just random names with "-a" tagged on the end. I loved Blair's character. Usually they make Barbie's character perfect and just a teensy bit wrong or different, but Blair had problems that she worked through. My only gripes were these:
The last scenes were a tad bit weak. Not bad, but the ending just wasn't quite in step with the rest of the movie. I wish they had put more work into Isla's song rather than just getting a good beat and throwing random words like "Fabulous" and "Yeah!" and "We rule the school" in.
The change of format in the end credits...a sparkly pink, textured background instead of the traditional black. I know, I know, it's minor and nit-picky, but it just seems symbolic of how they continue to move further and further away from tradition and old-schoolism.
And of course, BARBIE WAS VOICED BY DIANA! That will be one of my cons each and every time a Barbie movie comes out and Kelly isn't Barbie.
So all in all, I'll give it 4 and a half stars...

You guys beat me to it. What more can I say?

I'd give it 4.5 out of 5, and I'd definitely say it's the best modern BM. (The only reason it isn't 5/5 is because some parts niggled with me a bit, like the use of an Ipod and the transition scenes, and I wasn't the biggest fan of the fairies at the end, but those are the only problems I have).

One key thing here was that I actually cared about the story. It was interesting, and so were the characters. As FaithinChrist pointed out, Blair had problems. More importantly, she and the other characters had quite realistic problems. I'm not talking about the crown here, I'm talking about earning money, worrying about your family, not having confidence in yourself... things like that. I found it a lot easier to relate to Blair than Barbie in FS. She was just more... human, I think.
As for the other characters... well, again, the background characters were interesting, but I've always found them to be more interesting than the main cast in these newer BMs. Not the case here. I liked Hadley, Isla and Delancey, and Dame Devin really was a fantastic villain simply because she was so ruthless. She not only had Blair's family killed, remember; she was perfectly content to use her own daughter as a puppet and kick out a whole neighbourhood because their homes looked grubby (incidentally, can I just point out that Blair's neighbourhood looked like - gasp! - AN ACTUAL PLACE? I've walked down streets like that! Compare that to the overly shiny buildings in the other movies, and... well...) She's right up there with the Mouse King in terms of sheer evil.
While we're making Nutcracker comparisons, can I just mention Miss Privet? I love her. Absolutely love her. She's right up there with Major Mint in terms of characterization, and THAT is a very pleasant surprise. Yes, she's another character who will never get a doll because Mattel hates authority figures, but that doesn't change the fact that she's awesome.
I wish we'd seen more of Prince Nicholas, too. Blair's relationship with him seemed rather sudden, considering how little they saw each other.