Even though I was becoming more convinced of the theory about Snape having loved Lily, I really loved Snape's flashbacks - the fact that he'd met Lily even before she'd met James, and that it was his move into the Death Eaters that had lost her to him. Poor, poor, Snape. Unsurprising that Petunia had been jealous of Lily's acceptance into Hogwarts, though I never thought she'd have somehow written to Dumbledore. Wow!
Also liked Dudley's not-quite thank you - surprising.
Apparently people have been suggesting Snape's not dead - no body, no funeral, no portrait in the Headmaster's office, coupled with extensive knowledge of potions and healing after Dark Arts... that'd be wonderful. Betcha JKR soon denies it, though.