Congratulations on your new charge.
Here's my personal opinion on whether Dumbledore will come back alive or not:
I don't believe Dumbledore is alive. I believe, however, that we will see him - in the form of a portrait, the portrait that's up in the Headmaster's room. I'm sure it can give Harry some guidelines, but Harry will largely be on his own - because the portrait is not Dumbledore, it's simply an imprint of Dumbledore. I'm not sure how portraits work, but in my opinion, the portrait of a person will tend to do what the person did - but it won't be the person. It'll just kind of mimic the person.
I do think, however, that Snape is innocent. Yes, he did kill Dumbledore, but I'm 90% sure that Dumbledore told Snape to kill him.
One large effect of Dumbledore's death is that now Harry is on his own. Even though Dumbledore was not necessarily with Harry everyday, he was always protecting Harry. And now, Harry doesn't have that protection. He's on his own - he does his stuff, he takes the risks, and he doesn't have Dumbledore to run back to. That'll contribute to his overall development as a person/hero, and build his character. I guess it'll also allow us to see just how strong Harry really is.
Those are just a few pointers. I'll try and think up some more stuff, particularly more effects of Dumbledore's death, and I'll post it here. But that's all I have for now. Also, you can try out the website www.dumbledoreisnotdead.com. Even if you believe taht Dumbledore is dead, it's still a great site to go through.
