- Hagrid dies
- Snape does not die, but lives unhappily ever after
- Dumbledore returns in some noncorporeal form
- Harry kills Voldemort
- Harry becomes the Defense Against the Dark Arts teacher
This is my thought, too.
And I love this! I’m going to steal this theory and present it as my own to my family. 
My predictions:
- One or more Weasley(s) will die, and one of the ones that dies will be either Fred OR George. Having one twin die is just too tragic to pass up.
- Neville will take down Bellatrix LeStrange. I don’t think he will die in the effort, though. I think it will be the turning point where Neville becomes more certain of his power and becomes totally badass.
- Lupin and Bill together take out Fenrir Greyback.
- In some sort of fight, Gwrap will be killed, and Hagrid will fall into “Berserker” mode on the Death Eaters.
Hogwarts blows up in an orgy of magic destruction, on a par with a fuel-air explosive. Harry, Ron, and Hermione run out the front gate just ahead of the fireball.
Oh wait, that’s for the movie adaptation.
My predictions:
Harry, Ron, Hermione and Ginny all live.
Voldemort dies
Snape dies
So does at least one other Hogwarts teacher (or former teacher)
Bellatrix LeStrange dies
Peter Pettigrew dies, after repaying his debt to Harry
Snape is working against Voldemort
Snape was in love with Lily
R.A.B. is Regulus Black
Kreacher helped him steal the Horcrux.
The Horcruxes are: Slytherin’s locket, Hufflepuff’s cup, Ravenclaw’s wand, Nagini, Tom Riddle’s diary, and Marvolo Gaunt’s ring
Nobody loses their powers
Nobody dead comes back to life
None of the Dursley’s display any magical ability
None of the Hogwart’s teachers are traitors
#1. Harry will have to sacrifice himself to defeat and kill Voldemort.
#2. Harry will appear to die, only to be resurrected. This may happen before or after #1.
- Harry survives, along with Hermione, Ron, and Ginny.
- Neville does something sacrificial and heroic and may not survive.
- Aunt Petunia does something sacrificial and heroic and may not survive.
- Snape is bad, but on the side of good this time.
- Voldemort dies.
- Bill Weasley dies.
- All of the Malfoys survive, though diminished.
- Percy gets promoted through the Peter Principle.
I’m currently rereading book 6, so I can’t remember every detail of it. I’m probably forgetting something.
My predictions:
Lives:
- Harry (but loses his magic)
- Neville
- Ginny
- McGonagal
- Draco
- At least a couple Death Eaters
Dies:
- Ron or Hermione
- Snape
- Lupin or Tonks
- No fewer than two Weasleys (with odds on one of the twins)
- No fewer than two professors
- Several students we’ve come to love, including Luna
- Bellatrix (we can only hope by Neville’s hand)
- Voldemort–for reals this time
Other:
Snape is good.
Hermione is secretly working with Snape, who is helping them find and destroy the horcruxes. Harry finds out and the H/H friendship is temporarily damaged.
Harry learns to trust Snape, but only after Snape dies a redemptive death.
Harry learns to work with Draco, but only because he has to.
There is a huge coming-together of the four houses, which is instrumental in defeating Voldemort. Subpoint: The Hufflepuffs finally get their due–and revenge for Cedric.
Parseltongue is used to destroy one of the horcruxes.
There will be an important subplot involving a metamorphmagus.
Harry is betrayed by someone he thought he could trust–maybe Seamus Finnegan?
Harry’s scar is a horcrux.
Nagini is not.
Wormtail repays his life debt to Harry, very much against his (Wormtail’s) will.
It was Wormtail who loved Lily, not Snape. Wormtail thought he could make Lily love him if she were forced to “start over” when her husband and son were killed.
Percy is not redeemed. He remains a prat.
Draco discovers that Voldemort doesn’t actually care about blood purity or pureblood ascension; all he really wants is power and is using the Death Eaters as mere disposable tools to that end. This causes Draco’s defection to Harry and he brings some pureblood fanatics with him. Harry can’t defeat Voldemort without them.
And finally: There will be some plot element or manner of resolution that is universally hated and causes great wailing and gnashing of teeth amongst fans (myself included).
Pink-haired puppies.
Oh, and I forgot one earlier:
Nearly-Headless Nick voluntarily walks through the curtained portal, to move on to the Next Great Adventure he’s been postponing for the past half-millenium.
Right? And get this: he hasn’t read any of the books! He’s seen the movies, and I’ve told him about book 6 and some of the hot button issues, and he comes out with this dynamite theory. I always tell him he should be a writer.
I like this a lot. My own pet theory is that the dead can magically come back to life, and Harry is presented with the terrible choice of either bringing his parents back or killing Voldemort. Of course he chooses to kill Voldemort.
Snape is a good guy, after all, but dies.
Luna, Neville, the Weasley Twins and a whole lotta Death Eaters die.
Despite mourning those good guys who died, Ginny and Harry have a wonderful future together.
His scar disappears with Voldemort’s defeat.
Not a big fan, so this may be way off (and I have only one) -
Harry (or his scar) is the final horcrux.
I’m posting an idea I just came up which (probably) won’t be in the book, but still:
- Snape is neither “good” nor “bad”. He’s on his own side
- He knew all along he could defeat neither Voldemort nor Dumbledore
- And therefore he’s trying to play all sides against each other
The way I see it, he’ll try to get the “good” guys to defeat Voldemort so he doesn’t risk his own life, but, in the end he’ll get killed along with Voldemort.
That’s a good one. I thought we may see the veil come into play again but it was only in the abstract I hadn’t worked out a theory with it. I really like this.
I’ve been saying that, too. It would be a big sacrifice for him, but he can still have his happily ever after with Ginny.
There’ll be a lot of exposition, because she needs to sort a lot out. At some point we’ll find out what a “hallow” is, and how they can be deathly (unless we already know that; I haven’t read anything past “Goblet.”
She’s got to kill Voldemort. Then she’s got to kill off a good guy. She can’t kill any of the big three, or her house will be torched. Probably can’t kill Hagrid either, because he’s so lovable, and is not smart enough to kill. She already almost killed Ginny, so she’s safe. Neville’s parents were done in by death eaters, so he’s safe. She might kill Snape if she finally establishes him as a good guy first. Lupin is also a contender for death. If she goes for offing a trivial character a la Sirius, it’ll be a Weasly.
My vote: Snape.
Wormtail will go back to being a rat, but be stuck that way. Maybe Cruikshanks will eat him. No, Pratchett would do that, but not JK.
Hermione and Harry will become professors, and Ron will work for the Ministry of Magic. Hermione will marry Ron, Harry will marry Ginny. Draco will probably end up converting to good, or just be left to rot. He’s to stupid and cowardly to be evil, or killed. Lucius will end up in Azkaban. Neville needs to get married, too, if he lives.
I haven’t read volumes 4, 5 or 6 and I won’t read #7 either so I am uniquely unqualified to make predictions, but…
Snape - Dead
Harry gets to meet his parents somehow
Neville turns out to be evil and he may have some kind of a tail (or his ancestors had them)
Voldemort loses
By the end of the book:
McGonnagal (sp?) = turncoat
Snape = Deady McDead dead
Gestalt = annoyed at all the shippiness in the books, and hoping that the couples get divorced.
Gestalt
Nothing to see here.
Och, laddies, all th’ McGonagall hate! I don’t know if she’ll survive but she certainly will give her life for the Good.
As will Hagrid and maybe Ron.
Hermoine in her grief will find solace in being a spinster professor like McGonagall, eventually becoming Headmistress of Hogwarts.
Speaking of Heads, Dumbledore will not return except as a very helpful portrait. Most portraits are just echoes of the wizard’s personality, repeating catchphrases and being very vague, sez JKR (like Mrs. Black in 12 Grimmauld Place), but the Past Headmasters, she said, are a bit more aware of things and can give basic advice, while still seriously dead.
Harry will marry Ginny and they’ll have a green-eyed, red-haired kid named Minerva after McGonagall, or more likely Molly after Mrs. W., who I don’t think will make it. She’ll be spared seeing one of the twins, Ron, and maybe Charlie killed, but the grief will paralyze Mr. Weasley and reconcile Percy to the family, supporting his dad as he bumbles his way to the Minister of Magic position.
Snape is playing a double or triple game, with loyalty to whatever side is best for Snape, but will die in a way the readers know was supportive of Voldy but the wizarding world will think was on the side of the Order.
Don’t think Petunia will die but she will have to choose between her family and Harry and she’ll choose to help Harry.
Bellatrix–dead! Pettigrew–dead! Draco–dead! Lucius–dead! Niedemeyer–dead! Crabbe, Goyle and Narcissa–really really upset!
Voldemort, of course, death or worse. I like the Dementor’s Kiss idea, although I’d nuke him from orbit to be sure.
(Somewhat tongue in cheek.)
Harry - Pulls a Jesus.
Ron, Hermione, Ginny, & other main supporting cast - One will die, tragically, in Harry’s arms after an impossibly long goodbye speach, causing Harry to scream “Nooooooooo!”
Snape - Is pre-emptively taken out by an angry paranoid mob on obviously trumped up charges, leaving his final loyalties unclear.
Dumbledore - Still not resting or pining for the fjords.
Voldemort - Has a brief moment of triumph in which he takes over everything, only to have it all snatched away from him in satisfying comeuppance.
Everybody else - Who cares?
Harry, Ron and Hermione will live. I’d bet a LOT of money on it, and no, I have not peeked. No chance, none at all, that they will not survive the series.
In fact, Ron and Hermione will end up together.
Voldemort is defeated, of course.
Snape is working for the good guys.
McGonagall is not working for the bad guys. That’s ridiculous.
For all the other supporting characters, death’s about 50-50, save Ginny, who’ll survive, and Bellatrix Lestrange, who’s just as dead as Julius Caesar. Lucius Malfoy will probably die, but might also end up just disgraced It is certain at least one Weasley will die, because there’s so many of them it’s easy to offer one up to the bloodbath. A few Order of the Phoenix types will also buy the farm.
Draco Malfoy will play a more important part than he has in the past (I guess that’s kind of obvious from the end of Book 6) but he’s only 50-50 to die.
Neville will do something heroic. He’ll live.
So will Luna Lovegood.