The first reviews for the Half-Blood Prince have started to come out - and most people think it's magic!
Book reviewers have finished the novel already, with many of you lot not far behind! And while there is some criticism, many reviews are great.
Comments include "well crafted", "one of the best" a "real triumph" and the "darkest and most unsettling yet".
Of course, not everyone likes it. It's also been slammed for having too many sub-plots and focusing on past events.
The reviews written by adults and children vary a lot. Almost all the criticism comes from adult reviewers, whereas younger readers barely have a bad word to say about it.
Many children have branded it the best Potter instalment so far, and love this book because it finally gives pieces of the jigsaw that fans have been waiting for so long.
The Half-Blood Prince flew off the shelves on Saturday, paving the way to make it one of the best-selling books of all time.
Although figures haven't been released yet, it was expected to sell 10 million copies worldwide on Saturday alone - with two million of those being in the UK.
WH Smith reported the book sold at a rate of 13 per second in its stores, and staff at a Waterstones store in Edinburgh said "every other book sold" on Saturday was the sixth Potter book.
Many of you are already well into the book too. You've been e-mailing and texting us all day telling us your first thoughts.
Some of you have already been in tears, and one reader told us his parents had to take the book away from him as he was reading it in the middle of the night and was too tired!
JK Rowling led the launch event by giving a reading from the book at Edinburgh Castle. She also met 70 lucky young Potter fans who quizzed her at a youth press conference on Sunday morning.
And one very lucky boy, Owen Jones, 14, from Cardiff, won the only big interview with the Potter author after beating thousands of other children in a competition.
JK Rowling introduced Harry to the world in 1997 and since then the books have sold 270 million copies in 62 languages.