rayaluna brought up the "who will upset you most if they die in Book 7" question, so, here's my "what do I think the odds are on who WILL die in book 7" take.
Keep in mind I am working this out from the viewpoint of a reader looking for narrative logic and structure, which JKR has at least once buggered up in my opinion.*
1. Harry: Unlikely for a few reasons, though it would also work logically. Unlikely because a beloved hero's death is devastating to the reader, and a huge percentage of the readers are young people. Unlikely because nearly all of the text told from his limited viewpoint, and setting the denouement in any other viewpoint doesn't have the right feel for this long series. And I don't see Rowling foregoing denouement altogether. Still possible for him to die, though, because through the series the message of the books deals with "doing what is right" instead of what is easy, even to the point of death, and that death is not to be feared. Harry's been set on his path as one who must carry out his duty knowing it could mean death. But I still believe he'll be allowed to live, rewarded for his virtue by not being asked to pay the ultimate price. Losing people around him will have been payment enough. Plus, Harry's suffered enough to deserve a happy ending. Likelihood: 25%
2. Snape: Snape's necessary killing of Dumbledore will have Snape believing that the only justice is for him to die for the cause as well. He'll want to die. Harry will only be able to forgive him completely--and forgive him he must--if he's dead and Harry has the bitter sense of "too late" to bring him to full forgiveness. Harry's last lesson to learn, after doing the right thing and not fearing death and that the world isn't divided into good people and death eaters, is that things aren't always what they seem, and that Snape is one of the greatest heroes of his cause. Pity Harry didn't learn it at the end of Book 6--I might lay less high odds on Snape's death if that had been the case. Rowling still might pull it out of the fire, though, if she adds the lesson that those wracked with guilt don't always get to take the easy way out--they have to live with their deeds and their guilt, because life ain't always that merciful. Likelihood: 85%
3. Ron and/or Hermione: I actually think they have less of a chance of dying than Harry himself. Before book 6 I would have thought otherwise, but I think Ron and Hermione have been made into a unit with their romance, and romance adds a layer of protectiveness (see Lupin, below). I could have seen Ron dying, before, but now Ron's death would not be as strong a moment for Harry (and thus the reader) because Hermione's grief over losing her romantic partner would overshadow Harry's grief over losing his friend, and that's just not on. That diminishes the reader's grief, it doesn't heighten it. So I don't see it. Losing Hermione, on the other hand, suffers a little less from that kind of diminishment--you can't really see either boy grieving less over her just because one was dating her and the other wasn't, can you? (Yes, it is a boy-girl dynamics thing. Whether that's "fair" or not, it's there.) But I still think the likelihood of losing Hermione is low; it's too devastating. Losing them both? Only if it's a bloodbath ending and we lose lots and lots of people, which I think is not high on the odds, but I'm not ruling it out. Likelihood: 15%
4. Lupin: I'd have given him high odds before Book 6--after Sirius's death he was all but a walking "Send me on with the other Marauders" target--but, as I say, romance is protective. I don't think he's likely to go anymore. In fact, all of Book 6 was a large "Save Lupin" campaign, by taking him away from any chance to be another mentor figure for Harry. Likelihood: 25%
5. Ginny: Pretty unlikely. Harry did The Right Thing by walking away from someone he cared about hormonally but not yet deeply enough, in the name of his higher cause and his fears (you can argue if that's claptrap or not, but I think that's how Rowling sees it), and I think he'll be rewarded for that by her surviving. Reunion is possible but I think if it is it'll be vague, an open possibility that they have to rediscover who they are and see if they can form new, deeper bonds. Likelihood: 10%
6. Neville: I'd have put higher odds on Neville after Book 5. The Could-Have-Been-Boy Who Lived who could meet his end making some noble sacrifice, not because he's some false idea of what a hero is, but is a true do-what's-right Hero. But the lack of Neville-time in Book 6 puts me off that theory. Still, it could happen. Likelihood: 20%
7. Draco: Draco's death would make no narrative sense at this point, it really wouldn't. We got the teensiest glimpse, in Book 6, of how Draco's not a killer, but that's only the babiest of steps toward actual redemption. If he stays rotten!Draco and dies in the last book, why have shown us that glimpse at all? And there just isn't time--not unless the 7th book is titled Harry Potter and the Heir of Malfoy--to show us Draco reaching his redemption and dying in some spectacular sacrifice before the series ends. There's time, however, to have him at least come to see the error of his ways and stay alive, with the hint at possible redemption in the future. And even if there is no hint of redemption, he's still a kid. Killing him as "punishment" would be wanton. (I will say, though, that I can see his death serving as punishment for his parent's misdeeds--but then we'll have to see that effect on Lucius and Narcissa, and both of them will have to stay alive to atone.) Likelihood: 10%
8. Voldemort: Sure, he deserves to die. The likeliest ending is his death--shoot, it's in his name. Justice demands he be shown he can't cheat death. And it's the easiest ending. Still, Harry might be confronted with a "I can't kill him or it makes me no better than him; screw prophecy," moment that are classic endings. Of course, the other classic addition to those take-the-villain-into-custody endings are the villain-gets-killed-anyway-when-trying-to-escape denouements. Likelihood: 95%
9. Fred or George: I have my suspicions on this one. I think most of us have a bad feeling all of the Weasleys can't make it. So, which? Arthur or Molly? I'll concede they have a fair possibility of dying, since parents would give themselves for their children any day. But they haven't proved to have much of a record at protecting their children, since their children refuse to stay at home and be safe. I'm up in the air on them. Bill? Well, he's already had his brush with danger and made it. Charlie? Yeah, that'd be a cop-out, wouldn't it, kill the Weasley with the least screen-time. Percy? There's a question, isn't it. I think Percy's less likely to die because he fills a greater function in the books as the Black Sheep of the family who doesn't die, but has to be dealt with, in all his never-really-fitting-back-in glory. But the twins--killing off one of the twins would be one of the cruelest hurts for the reader (even if the reader doesn't much like them); the remaining twin's grief would be our grief. And while it'd hurt, it still isn't one of the "main" characters. Nothing so unforgivably awful as losing Ron or Hermione. I really can see this happening. Likelihood: 35%
10. Bellatrix: Toast. Likelihood: 99%
11. Pettigrew: I give him Snape-like odds. It'd be easiest for him to die either as fitting punishment and/or part of whatever redemptive efforts he might make at the end, but he might survive just because Rowling might not allow him the easy mercy. Likelihood: 85%
12. Luna: Though I think it's unlikely, I can see her being the innocent person closest to Harry who does get offed. She'd be a good candidate for a set of smiling last words that add up to a refrain of Dumbledore's, given what she's had to say about the Veil: "Don't worry, Harry...one day I'll...see you all...again." Likelihood: 20%
13. Lucius: I think it's most likely he's left to serve his sentence in Azkaban and we don't see him again. Though if he does escape, he's doomed. Likelihood: 40%
14. Hedwig: This saddens me so much I can't even contemplate it.
ETA: Oh! I left off 15. Hagrid! I have to give him fairly high odds, as he's the last of Harry's mentors, and would consider it an honor to die protecting the boy. His death would be a fairly-played emotional wrench for the reader. Likelihood: 40%
*What I mean by JKR having buggered up once before is in regards to Sirius. I've come to think the reason Sirius's death bothered me so is not just because he was someone important to Harry but because it's not a death that the story structure supports. It made no sense to introduce Sirius in Book 3, set Harry up for an eventual ending where he and Sirius become something of a family with each other, and then kill Sirius in Book 5. Rowling has said she had to remove Sirius because Harry had to lose his mentor figures, as the classic hero must go to fight his battles alone--but it still did not make sense to introduce Sirius so recently, in that case. As someone else said, killing Sirius only orphans Harry twice, which wasn't necessary and makes for a sloppy narrative.