Harry Potter readathon latest

They always do it the Harry P books. Once I start reading, I just can't put the damn things down. I've raced through the Prisoner of Azkaban and Goblet of Fire and am two thirds my way through the fifth, the Order of the Phoenix or the 'really angry book' as I prefer to call it.

I've noticed lots of things that I think are significant as I read through, most of which I've immediately forgotten. One that does stick in my mind is this bit from Goblet when Harry is explaining to Dumbledore how his own blood had been used to revive Voldemort:

'He said my blood would make him stronger than if he'd used someone else's. He said the protection my mother left in me, he'd have it too. and he was right - he could touch me without hurting himself and he touched my face.'

For a fleeting instant, Harry thought he saw a gleam of something like triumph in Dumbledore's eye. but the next second, Harry was sure he had imagined it, for when Dumbledore had returned to his seat behind the desk, he looked as old and weary as Harry had ever seen him.

I'm not sure what it means but it has to have some bearing on what happens in the final book and Harry's or Voldemort's potential demise. Also why triumphant - is Dumbledore just gloating that something he foresaw has indeed come true or that Voldemort is finally learning the power of ancient magic? A little out of character perhaps. Or does this mean that he thinks it might in someway help Harry in the final battle?

Answers on a postcard no later than 20th July please.