I like this chapter much better.  It's full of action and character development.

The first lines make me feel Harry's numbness and the slowness of time for a mourner, as you list his oh-so-mundane actions.

The sardonic humor is back: "The Daily Prophet had reported twenty deaths, which meant there were at least thirty, plus more no one knew of."

The characters of Dudley and Petunia are very true-to-canon in their conversation: she gives right in to him after a very mild sparring match.

And I like Harry's relationship with Petunia.  She has always seemed too-bad-to-be-true in the books.

And Snape's letter is again very like him, except for one error (which may not actually be an error because it fits his sarcastic humor perfectly): "The Dark Lord does not know your exact location, but thanks to your idiotic jaunt today, he knows the approximate area, and has planned to severely attack Little *Whining* tonight."  : ) Tee-hee.

Your writing has a lot to recommend it. 

I like your sense of humor:

• "Harry had returned to the hell more commonly known as Privet Drive."

This is an especially touching passage (I've felt this way myself when mourning the loss of a friend):

• "Uncle Vernon had not locked up his things,... but after a few weeks of crying hysterically every time he saw something that reminded him of Sirius [Harry] locked them all up himself."  

And this description shows promise: 

• "The layer of cheerfulness was like a balloon that had been blown larger than it could withstand. To the world it seemed strong, but Harry only had a single thought to cling to: Padfoot and Prongs were united. He used that thought each time his façade broke. When it did, he would carefully repair his joy and then stretch it out again and rebuild the mask.

It is a decent metaphor, though the words 'facade' and 'mask' interfere with the image and the feeling of tension in a balloon about to burst.

And I like your explanation of the Death Eaters' strategy post-OotP:

• "The mistakes that Voldemort had made in his last reign were corrected as he built a new regime. The aurors, and members of the Order of the Phoenix were targeted specifically and the Ministry was practically ignored. "

The rest of the chapter, except for the sketches of Petunia Dursley and Snape, is a little too dry for my taste.  What I mean by that is it seems like you are just hurriedly dumping a lot of facts in at the end to pave the way for the real story.  This is understandable, but given the talent you showed in the first paragraphs, it makes me think you could have given them to us in a way that would continue to engage our imaginations.