The first piece of the puzzle is source material:

This book by Alice Sebold is both heartwarming and depressing, full of life and death, joy and sadness that it practically begs to be put on the screen. So, brilliant source material: check!
Then you need a director to helm the project who truly believes in it and has the knowhow to put a fantastic novel onto screen.
Enter Peter Jackson. With his relationship with the Hobbit falling by the wayside it has given him a chance to pursue this passion project which he has talked about for a while. With his previous experience on The Lord of the Rings he knows what it takes to adapt a beloved novel into a classic film.
The source material and director can only go so far without the perfect cast to carry it all out.

Rachel Weisz will be playing one of the main roles in the film, Abigail Salmon. Even though I am slightly biased by my infatuation with her, she is genuinely gifted as an actress and has the right emotional range to portray this grieving mother.
This film is still far from being perfect but it is on its way. The rest of the cast will be very key. But announcing Rachel as the first is surely a good sign. Does anyone know of any other projects that could be this good?