And Snape is the half-blood "prince" -- he isn't realy a prince, though. His mother's last name was Prince and his father was a muggle.

Malfoy had a chance to kill Dumbledore but he didn't (couldn't? - didn't want to?) at the last moment, that is when Snape stepped in and did it.

I'm not really into it, either. I bought the book for my mom and just kinda skimmed the last couple chapters last night.