Everything that has been mentioned above, I want to second.
I’d also like to see something more of Hermione’s Muggle Life. We’ve seen Ron’s at The Burrow, but nothing of her life.
Snape’s story and background is sadly lacking.
McConigal’s back ground is even more lacking.
Will we see Gilderoy Lockhart again, even in his state of amnesia induced brain? (that would be comic.)
What will happen to Bill and his werewolf bite? Will he change at Full Moon? Will he have sharpened senses? Will he have dog breath?
Will the house in Godric’s Hollow still be standing? Will it be rented out if it is there? What will Harry find?
What is up with Trevor the Toad? He seems the most worthless pet.
Most importantly…How long will we have to wait?!!111!!!
This is worse than being 12 all over again.
If Hogwart’s opens up, who will be the DaDA teacher?
Will Lucius Malfoy break out of prison to join Voldemort or rescue his son? (I do enjoy his appearances.)
Neville will save the day and break the curse ( or whatever) on his parents.