After being so disappointed with other films from books (namely The Other Boleyn Girl - which had very little to do with Mary Boleyn) I wanted to read the whole thing before watching something that has big chunks missing.
After a bit of a weird start it's actually turning into a good read. I am determined to try and finish it as I hate reading books so far and then giving up. I don't see the point in starting a book if you're going to give in before giving it a good bash.
BTW - I'm pleased to hear that that the last Harry Potter book is to be made into 2 films. There's too much in it to cram it into 2 1/2 hours.