Just finished, and here's my sense of things.
Dumbledore will not be returning.
Hogwart's will continue on, with McGonegal as headmistress, though Harry will not attend. Book 7 will take a new direction, with Hogwart's in the background as the focus shifts to Harry's search for the Horcruxes.
When the 7th book starts, Harry will have mastered Apparition and matured as a wizard, much as Luke Skywalker did between The Empire Strikes Back and Return of the Jedi.
Ginny did, in fact, anticipate and accept the breakup. If Harry survives and Voldemort dies, they might get back together. It's just as likely that Ginny will move on, as JKR seems to inject more realism into each successive book.
Snape is evil through and through, and always has been; Dumbledore's unwavering trust in him was his Achilles' Heel in the most classic literary sense--the tragic flaw that was his undoing.
The final battle between Harry and Voldemort will occur on the grounds of Hogwart's, and the nature of the school itself--its history, its secrets--will be of crucial importance to the final outcome. The school will possibly be destroyed in that fight.
And finally, my most off-beat, irrational, baseless prediction:
Harry dies taking Voldemort out. As others have said, the prophecy is rather lame anyway. I just have a gut feeling JKR will end with a bang, which, in my mind, would be fitting. There's little place for a Harry Potter in a Voldemort-less world.
Rowling's entire tale is a rather ingenious (if, at times, pedestrian) retelling of the heroic epic that has been told and retold throughout human history:
In many myths and folk tales, a hero is a man or woman traditionally the protagonist of a story, legend or saga, who commonly possesses abilities or character far greater than that of a typical person, which enable him or her to perform some extraordinary, beneficial deed (a "heroic deed") for which he or she is famous. These powers are sometimes not only of the body but also of the mind. Heroes are typically opposed by villains, and are aided on their quest by a sage or mentor. At the beginning of the tale, the hero is often an orphan or foundling lacking potency or virility, but through the journey gains the strength and resources he or she needs to face the villain. These resources usually come in the form of spectacular or magical items, as well as training and advice from the mentor, whom the protagonist eventually surpasses.
