<p>R.A.B. is most likely Regalus Black- Jk Rowling introduced him to us briefly, but we never fully understood why he died, (Sirius could only guess). There must be some important role for him to fulfill.</p>
<p>As for Dumbledore's death, I'm convinced that Snape is good. There was a conversation earlier in the book where Snape told Dumbledore "you are asking too much of me" [ie: kill you]. Dumbledore would never ever plead for his life; instead, he was pleading for Snape to kill him, because Snape did not want to. Furthermore, JK Rowling says that Snape looked at Dumbledore for a second. Maybe some legilimency went on there? Also, Snape killing Dumbledore on Dumbledore's orders resolves many issues: Draco does not have to become a murderer, Snape is allowed to remain on Voldemort's inner side, Snape also doesn't have to die due to the Unbreakable Vow, etc. </p>
<p>If you read the scene where Dumbledore is killed very carefully, you can really see that Dumbledore knows everything Malfoy is telling him. In fact, he is manipulating Malfoy to tell him these things. Dumbledore already knows everything, but he wants Harry to hear what Malfoy is saying. Thus, Harry comes out of this scene firmly convinced that Snape is a killer. Dumbledore WANTS Harry to believe this. Harry is terrible at Occlumency (ppl can always read his mind); thus, it is much safer for Harry to believe everything at face value, just like everyone else. If anyone did read his mind, they would see that he thought just what everyone else thinking- snape was a murderer. This would protect both Snape and Harry; no one could ever find out that Snape was on Dumbledore's side--Snape and DUmbledore were the only ones who knew.</p>
<p>I actually heard an interesting perspective on Dumbledore's death yesterday. The basic idea is: Dumbledore made a horcrux from Aragog. After all, Aragog's death seemed pretty pointless, right? It must have had a more significant meaning. So basically, Dumbledore killed Aragog and made a horcrux. Thus, when Snape "killed" him at the end, he did not die, since part of his soul was encased elsewhere (hence the rising phoenix at his burial). If this idea seems totally impossible, there's another variation: spider blood has some elixir-type qualities (sort of like lotr), and Dumbledore drank it so that, when Snape "killed" him, he would still somehow come back to life.</p>
<p>So I'm not sure if Dumbledore is dead or not, but Harry certainly will have to slug things out on his own by now. I'm curious though: how will Harry know how to destroy the other horcruxes if he finds them? Maybe Snape will help him? Who knows...</p>
<p>Well, we'll eventually find out in ::several:: years!</p>
<p>*<em>edit: was anyone else sort of surprised that Slughorn was a Slytherin? Idk- he seemed so much nicer than all the present Slytherins! And, contrary to what Hagrid said about all slytherins, he doesn't *seem</em> to have gone bad.</p>