The fifth question posed by Scholastic is "Where are the Horcruxes?". I'm going to use this as a small excuse to expound on some of my more brilliant Voldemort and Snape insights ;)
First of all, one thing Jo mentioned (or rather, hasn't mentioned) is the significance of the look Dumbledore gets on his face after Harry comes out of the maze in book four-after Harry has related the story of the graveyard to him in his office. Harry tells him that Voldemort took some of his blood and then Dumbledore gets a look of triumph on his face. We know it's significant (see numerous evasive interviews), but she hasn't explained why. Here comes the brilliant insight-Voldemort having Harry's mother's blood running through him does allow him to touch Harry-but it does also give him traces of that love he despises so much. He's taken into himself some of the power that destroyed him in the first place. Wouldn't that make him easier to kill the second time around? He is both strengthened and weakened by the stuff...
As for Snape (I was listening to the end of book 4 at work today), I think I have further proof as to why he would be on the good side. It's at the end when Dumbledore and Fudge are having their spat about whether or not Fudge should get rid of the dementors/admit Voldy is back/etc. when all of the sudden Snape rips back the sleeve of his robes and shoves the Dark Mark into Fudge's face in an attempt to convince him to take Dumbledore's advice. Why would he do that if he was on Voldemort's side? It wasn't necessary, really. He didn't need to prove to Fudge that he was on the good side, Fudge already believed it. So did Dumbledore. It was a blatant attempt on his side to convince Fudge that Voldemort was back. Why would he do that if he was on Voldemort's side? Having Fudge live in denial is what Voldemort wants-it's why he lays low for virtually all of book five. If Snape was working for Voldemort or intending to turn to his side again, why would he do such a thing?
Anyway. Onward and upward.
Horcruxes. Interesting things, aren't they? Kind of morbid. What do we know about them (or think we know-Dumbledore could be wrong)-there should be seven total (including the one still in LV)-two are destroyed (ring-representing his pure blood ancestry, and diary-representing his years at Hogwarts). That leaves four tokens left, plus the big man himself. Some people suspect that there are more than this, but I doubt it. Jo has said that she considers 7 a 'powerfully magical number'. It's symbolic in many ways-eight just doesn't have the same weight. So laboring under the assumption that there are four (plus one) left for Harry to destroy, and Dumbledore was right about the cup and the locket-we've got two variables.
Dumbledore suggested that he thought Nagini might be an interesting option for a Horcrux, but I doubt it somehow. Voldemort does have curious control over her, but he is like that with most people that aren't horcruxes-and it seems so unlikely that he would put his trust in putting a horcrux in something that's living and has the capability to get away from him (even if the chance is small). It just doesn't feel right. Nagini is a mortal snake-it does not seem likely that he would place a bit of his soul into something that could die. Not to mention the significance of having the remaining four horcruxes come from the houses of the founders-it ties together the significance of the school rather nicely. Besides-one of the most important parts of the hero's journey is the part where the apprentice overcomes the master-it happens when Frodo is able to destroy the ring and Bilbo/Isildur couldn't-it happens when Luke is able to overcome the Emperor/Vader when his father/Obi wan (respectively) were not. It's an important part. Harry has to discover some of this on his own. Which is why I hold to the theory that we have the locket (Slytherin's, and either at Grimmauld still or scattered by Dung-the prat), the cup (Hufflepuff's-the location is not known, but the cup is said to have some magical powers of it's own that we don't know about).
Is Harry a Horcrux? No. No. No. Orson Scott Card has a really interesting theory in favor of this that seems rather interesting-it would be symbolic for Harry to be able to survive and destroy the horcrux inside him with the love that runs through him-but I don't agree any more. That symbolism can be achieved in other ways. It just doesn't seem likely. The little we know about how Horcruxes are made works against it. We know they are created with murder. We know that it is very deep, dark, difficult magic that is deliberately done (wow. consonance). Voldemort would not have been in any state to do so after he tried killing Harry the first time. And then there is the issue of Voldemort trying (unsuccessfully) to kill him five times now (when he was a baby, with the philosopher's/sorcerer's stone incident, in the Chamber of Secrets, in the graveyard, at the Ministry). Why would he kill something he's put a horcrux in? And then there's the question of love inside Harry-how could a piece of Voldemort's soul live inside Harry when he is so full of love for various people-the Weasley's....Ginny, Hermione, Sirius, Dumbledore, his parents...etc. etc. etc.? Voldemort can't stand to possess him long when they're in the Ministry-it doesn't seem likely that a piece of his soul could either. He could have unwittingly put one in Harry but...no. Just ...no.
So where are they? Well-let's think of what we know.
We know that one was in Hogwarts already (the diary). We also know that it wasn't put there by Voldemort-it was brought there by Lucius via. Ginny. We (think) we know that the locket is (or was) at Grimmauld Place. So while I think it's safe to assume that most of these remaining bits of Voldemort's soul will be in the place he intends them to be, it is possible that we will come across them in insignificant places (or places that they weren't intended to be). I would venture a guess that there is another Horcrux in the Hogwarts area-Hogwarts was so important to Voldemort it would seem a little ridiculous not to have one there-granted Dumbledore has probably done some searching, but he's been wrong before. The Riddle House was a murder location/his father's home/his temporary home at the beginning of book four-there could be one there. What about the orphanage itself? What other places were particularly important to Voldemort before he tried to kill Harry? It feels like we still need information about him before we can make that assessment. His life is still pretty sketchy. He worked at Borgin and Burkes for a while but I wouldn't bet on one being there-too likely that it would be sold by the greedy shop owners. Though he could have hidden it fairly well. I would also bet that there could be one somewhere in Gringotts- I don't know how special/significant this would be in terms of Voldemort's past, but it is supposed to be the safest place to keep something next to Hogwarts, and we learned a ton about it in book one that has been virtually ignored since then. It would be a pretty brilliant place to store a horcrux. It has a built in security system. There isn't a ton we can do with this information based on what we know of Voldemort's past-I think most of this will just have to wait for discovery in the next book...which is two weeks away! I will have it in my greedy little hands two weeks from now exactly. Scary.
While I'm on this track-a word of warning to you all (wherever you are)-our local paper published yet another reminder of how awful Death Eaters can be (some people call them 'the worst sort of Muggle'...I like to be a little more mean)-be wary of those who would spoil the book for you if you care. Avoid the internet, television, radio etc. until you've finished the book. People will do nasty things like make up login names revealing the dead characters/shout who dies out loud to people in the bookstore/make signs/t-shirts...everything. It's horrible. Granted, this book is fraught with death so I doubt any nay-sayers will be able to ruin everything but all the same, I plan to go armed with headphones and really loud music to escort me away from the bookstore and back to my bedroom, where I will proceed to barricade myself with some popcorn and Dr. Pepper for company (and maybe a chamber pot to save myself time...only joking)-until I have safely finished the book and my emotional purge. I didn't think such a thing would be necessary until the newspaper gave every obnoxious teen in my town the idea, but there it is. I'm not taking any chances this time. Blinders on-earphones in-eyes on the prize. You have been warned.