Well, I finished reading Harry Potter and the Half-Blood Prince a week or so ago. In my opinion, the best book of the series, well worth a read or even two.

Here are a few musings of mine on the seventh book, and about you-know-who-number-1 killing you-know-who-number-2 and whether you-know-who-number-1 is really evil and you-know-who-number-2 is really dead. :)
Simple highlight the following to read it:
OK, Snape kills Dumbledore - well, here's the deal.
1. Remember that Dumbledore is basically Mr. Phoenix - meaning that him coming back in book seven is totally plausible and probable. He's too much like Gandalf to not come back. ;)
2. Snape kills him as a result of his Unbreakable Vow from Chapter 2 - I think it is very possible that Dumbledore knew about this, and that he and Snape set the whole thing up so that a) Draco didn't kill him; b) Snape now has Voldemort's complete trust; c) Voldemort thinks Dumbledore is dead. Remember that Dumbledore knew Death Eaters were coming up the tower and did not "Accio" his wand even though he easily could have, also that he froze Harry so that Harry wouldn't defend him. It was clearly a voluntary death.
3. Snape does not kill Harry at the end even though he could - in fact, he saves Harry, and also teaches him a few things on the side!
So...I think Snape is a bitter person, but I also think he isn't "evil" in the sense that he is against Voldemort - probably wants revenge.
Well, there we go. :) My musings on Potter and the HBP.