Well, I finally read it. Darn good reading, too. Now, I only read it once, so maybe it'll grow on me later on, but I still think PoA was the best one. HBP is tied in second place with OotP, which didn't take the top spot just because of Harry's excessive whining. HBP had lots of character development, which is always good, but it was mainly a Voldemort prequel. Also, having the Dumbledore thing spoiled months in advance may have ruined things a bit as well...
And about the bit about JK saying Sirius would be back in some way, I guess she meant what we saw in HBP, right? I mean, Tonks' Patrono (sorry, don't know the word in English!) took the form of a quadruped, and Harry had the feeling it was Padfoot (is that it in English?
).
And comenting on what the future may hold, someone mentioned Snape becoming headmaster. I haven't made up my mind simply because, as many stated, JK likes a twist, and the whole "he's a traitor" plot was very much in-our-face the whole time. So she's either planning a curveball down the road, like "you thought he was evil but he's actually nice" or she really just tackled this head on because she knows by now we're expecting hidden messages in everything.
McGonagal will be headmistress, now, and Slug will probably stay teaching Potions. We don't know if McGonagal will keep her teaching and House Director duties, but we do know we'll need another DaDA teacher.
If Jo wants to go for the totally sad ending, she could have Ginny dying to save Harry, and then a double KO between Harry and Lord V. Although I see him not dying (just because killing him would be too easy), and Ginny spending the whole book trying to show him that she's just as strong as him and that he needs her, much like James needed Lilly to be centered.
For the epilogue, I don't really see Harry as an auror (don't know if that's the word). Hogwarts was his true home, and everyone he considers family came form there or were happy there at some point. All 3 of them will probably become teachers. Harry teaching DaDA teacher, Mione teaching anything, and Ron... Well, Mione will probably find something for him. I see Mione as headmistress, not Harry, like many have been speculating for years. Actually, maybe Mione will become minister, and Ron will have some big shot job there as well.