Indeed, in book 5 it's so...weird to have Dumbledore ousted. I was going to say that it was not at all the way it feels when Dumbledore is away briefly in book 1 or when he is ousted in book 2. But now that I'm thinking about it, those incidents have a strange, displaced quality to them, like the way sound is snuffed out during a heavy snow fall.

But if it had gone a little differently... who knows?
That's exactly how I view things. I think Draco has been filled in on Harry's little excursion with the hat. It seems the sort of thing that would get out at some point and pass into rumour lore of Hogwarts. And Draco is more tormented than ever, thinking, "if I'd only gotten that mudblood loving fool as a mate at the start, he'd 've chosen Slytherin and I would be Voldemort's favourite among the younger set!" Or something along those lines.