Harry is reveled as the 7th Horcrux. Not exactly a surprise.

One character names his first son Albus Severus after the two bravest Headmasters Hogwarts had ever known.

Dumbledor mistrusted his own desire for power; a desire that caused tragedy in his own family while a youth. This kept him from accepting the post of Minister of Magic.

Harry's invisibility cloak turns out to be one of the Hallows, the others have been seen in the other books, but not reveled as items of extraordinary power until this book. They all notionally belong to Harry as family heirlooms.

Dumbledor's power over Snape is reveled as Snape's remorse over the death of Lily, Harry's mother. Snape loved her since they were neighbors as children. That did not stop him from truly hating Harry through his father, James. Snape has a secondary role in this book, and I found it curious that Snape's admonition to Harry to 'cast spells without speaking' is not expanded further in this book. Snape's death is pointless, he is never discovered as a traitor by Voldemort, and is killed 'with regret' by Voldemort to further an aim.

There are losses in the Weasley family, known students murdered, as well as children left orphaned by the deaths of their known parents. The anger of Mrs. Weasley is awesome to behold. She shows more kick-ass Witching power in one short scene than Voldemort does in the whole series. Her powerful and seemingly unbeatable opponents are meat in her hands. The description of the area around her personal battle being cracked and melted say it all..."she was fighting to kill".

Draco Malfoy's love for his parents, and visa versa, saves them all. Malfoy names his son Scorpius...who peaks the interest of a Weasley granddaughter.

Voldemort's end is strangely mundane...as duly noted in the book. I would think it was because Harry has stripped Voldemort like an onion, layer by layer, for several books. At the end, there was only Harry and Voldemort. By this time his power is diluted, but he is too self-focused to believe it, and his followers are too cowed by him to notice it.

When Voldemort used Harry's blood as a charm to revive himself in "Goblet of Fire", Voldemort laid the foundations of his own doom. He had given Harry a bit of himself when he tried to kill Harry as a baby, and got a bit of Harry back when he used Harry's blood. The prophecy said that "Neither could live unless one was killed", but the blood charm said "Neither could live unless both lived". It made for an interesting ending.

Their wands were twins, nearly had a life of their own, and cause complications whenever they would meet thru the books. At the end, they both had borrowed wands...both of them actually belonging at one time or another to Draco Malfoy.

The ancient and powerful Deathly Hallows were an unbeatable wand (at one time held by Dumbledor), a stone (set unknowingly into the Riddle ring), and an invisability cloak. Created by three powerful brothers, together they could hold power over death.

One final thought....

If you want to attack Hogwarts castle, bring everybody you know. And bring everybody they know.