I can't believe no one started a thread already.
I picked my copy up on Saturday afternoon. Started reading at 2PM and finished at 2am with breaks for dinner, shower and 2 lengthy phone calls. I pretty much barrelled through it because I had to finish before Sunday day. Had tickets for Sunday's Yankee game and did not want to overhear anyone talking about HP7. I did keep myself from peeking at the very end and will likely go back and read certain sections to make sure I understood the explanations completely.
Anyway, I thought JK Rowling really did a great job at explaining everything to date. Parts made me sad and others somewhat triumphant. Can't say much more because I don't want to spoil it for anyone.