My verdict on the book so far, it's smart and incredibily fascinating and is in no way going to get boring from here on out.
My thing, which I believe is in everyone's minds once they read the book, is that I totally, definitely, absolutely despise and HATE that Umbridge woman! When I read what she did to Harry when he was in detention, I drew the line there. She is a fucking bitch in my book, and I have yet to understand how the Ministry of Magic could have such cruel people in their organization. But, of course, it's the government so that's one reason there.
There was one thing that I thought while I was in the middle of the book: this is not going to be a good year for Harry, is it? And obviously it isn't.
But the part that I will never forget is at Christmas in the Grimmauld Place when Sirius was singing Christmas carols. Though it was a small scene, it made me laugh and smile. I was just so happy that Sirius was finally happy for the holidays. Also another scene which was brief (though a major point of the book) is when Harry was going to Platform 9 3/4 and Sirius came along, in his dog form, and he was chasing his tail and cats just to entertain Harry, as well as enjoying his time out of the house. Even though Lucius Malfoy saw him at the train station, I was glad Sirius had a little freedom.
Well, that's it for now. I hope to give a full verdict on the entire book as soon as I finish it.