We still want to know....
What happened in those 19 years? What were their careers? How is poor George coping without Fred? Who remained friends with who? Who married who? Were there anybody else we knew amongst the 50 bodies after the battle at Hogwarts?
Where did Sirius actually go behind the veil? How did Lupin and Tonks actually die? Was little Teddy a werewolf? Did Hagrid receive an apology when they found out he didn't open the chamber of secrets?
We would even love a book on the Marauders time at school, so we could see the adults during their child hoods and their time at Hogwarts. We could see Voldemorts first attempt to power and how the original order dealt with everything. It would be such an amazing book which would also answer questions about Lily and James, what careers they had for example.
Could we please, please, please have an 8th book of some kind? The future looks empty without them!