For a Harry Potter fan, this book adds further to the fascinating story of magic world though Rowling has used this book primarily as a precursor to her final book. The story turns even more complex in this book, building up the climax which the final book will end.
Sixth year for Harry, its an year of emotions and self discovery. The plot thickens where the teens get pulled into the dark war between good and evil.
Though the book seemed to drag (compared to Order of Phoenix) without much happening during the most part of the book except for teenage love games between Ron and Hermione and discovery of Harry's attraction to Ginny and Harry's struggle to get over loss of Sirius Black, Rowling picks up suddenly in the last 2 chapters where most of the action suddenly builds up and shocks the reader with the final killing of the pillar of strength for Harry and rest of the wizard world.
Rowling brings up more complex magical terminology which is interesting to read - Horocruxs or pieces of souls which enables 'you know who' to survive, has raised the reader's expectations even more for the final book. Rowling has skillfully linked this book with the story built till now giving more detailed magic related theories. What Rowling brings in the last finale is much awaited...