Ideally she'd have written all the books before the first one was published, the way Tolkien did with the Lord of the Rings. Or at the other extreme, perhaps, written them in monthly installments, like Dickens.

Book size chunks, coming out every year or so, but trying to contain a continuing story line, and heading towards a predetermined ending, must be the hardest one of all. Especially with all the hype and the films and all - it would be virtually impossible for her to avoid being affected by the way the characters have been portrayed in the films, because she knows all her readers are already seeing them that way.

I have a feeling that at some time she might come back and revise this volume and extend some parts of it - not so much because that would be a way of milking the market, like a "directors cut" film, as because there are bits that need amplifying, such as the Tonks/ Lupin stuff mentioned by several people, and the back story for Dumbledore's blackened hand, and I can imagine her wanting to do that kind of thing, because she clearly cares about getting it right.