OK, I only have one more day before the final Harry Potter book comes out, so I had better get my theories up quick. Obviously this contains spoilers through book 6.
Harry: Lives. If JKR followed the normal heroic tradition he would have to die (Achilles), or at least not have a place in the world for himself (Frodo), but he will make it through, with a little help from his friends (and a lot of help from his enemies) and a strengthened relationship to boot. (He and Ginny will have trouble because he is out Horcrux Hunting but get through it for the better.)
Snape: Lives, or maybe that’s just because I want him to. He probably needs to die to vindicate himself, I just have this crazy dream that Harry will finally be able to see past the obvious conclusion and realize that he is good and be able to do something to save him at the last minute. Unfortunately Harry will probably remain clueless until it is too late.
Horcrux: RAB was Regulus, Mundungus stole it from Kreature along with hopefully some others that RAB got already, but I’m not holding my breath. (I really don’t want the book to be a treasure hunt.) Harry is one, but Voldemort broke it by using his (Harry’s) blood in bringing himself back to life. That would explain why Dumbledore was happy when he heard about how Voldemort came back. That’s my crazy prediction.
Slash: Harry/Ginny, Hermione/Ron, Tonks/Lupin (Dead), Bill/Fleur. Watching harry ginny and hermione ron be set up from the beginning has been one of my favorite things about reading this series.
Growing Up: Harry will finally realize that controlling his anger is the only way he can win, and that what Snape was teaching him the most important lessons of all: Close your mind and your mouth, occlumency and silent spells will be key, and don’t do the unforgivable curses. Leave that to Snape who will finish the job. The only question is how fast Harry will figure this out.
Deaths: Voldy, Wormtail (owes harry a life debt after all), Lupin (expendable and tragic, also only remaining father figure?). Not sure about the Weasleys, but I could easily see any of the non slashed hogwarts kids getting the axe. Cost of war and all that.
Now all I need to do is find the time to read the final book BEFORE SOMEONE SPOILS ME. I am warming up my brain to melt people with hate if they spoil me.
Update: Growing Up: I forgot one chunk of growing up that Harry has already done, at the beginning of OotP he is caught on the train with Luna and Neville by Cho and wishes that he wasn’t with them because they aren’t cool enough. At the beginning of HBP he defends them in front of others because he realizes that true friendship isn’t about being cool. They were willing to fight and die for him. I think that transition is one of my favorite moments in the book, and I hope that JKR will follow up on that in the next book, so harry doesn’t have to go it alone.