Albus Dumbledore's death at the end of Harry Potter and the Half-Blood Prince left many fans nothing less than depressed. However, it may be possible that Dumbledore will still be connected to Harry and friends in the final book. For example, in Chapter 14 of Harry Potter and the Chamber of Secrets, Dumbledore says, "...I will only truly have left this school when none here are loyal to me. You will also find that help will always be given at Hogwarts to those who ask for it." (pages 263-264)
Yes, this reference was written so that Harry would get help when battling Tom Riddle and the Basilisk at the end of the book, but could it be an indication for what lies ahead? J.K. Rowling has a history of writing clues or introducing characters that become important in later books. An example would be the mention of Sirius Black in Harry Potter and the Sorcerer's Stone. Sirius later becomes a significant person in Harry's life beginning in the third book.
