Jeez, I could write 20 pages on this subject, but I'll try to condense it. Here's what I think the horcruxes are...
X1) Riddle Diary
X2) Gaunt Ring
3) Locket (possibly at Sirius' house) -> I think it's understood that JK left us a little easter egg in OoTP about this locket. I think that the fate of it could be: A) Kreacher kept it and it is still at Grimmauld place B) Mundungus stole it and the trio have to find it (which could be the character they wanted to write out of OoTP movie and needed to keep in...read my earlier post)
4) Huffepuff cup
5) Unknown Relic (Could be something of Hufflepuffs/Ravenclaw)
6) Nagini (I think that is the last line of defense for riddle, having his horcrux so near him with something so loyal to him,but I'm not too sure )
7) Harry (Could have been inadvertently turned into a keeper of a piece of riddle's soul)
As for Snape being good/evil: he's "goodish". What I like so much about the character is that for him there is no white or black, but ALL gray. He's a tortured soul and a lonely man. He is trapped between his loyalty to dumbledore and his hatred for anything related to ANY potter. Since rowling has portrayed him and something of a genius, I think it's well within his power to know about all the horcruxes and possibly have a way to locate/destroy them. So I think he'll help the trio in the destruction of the horcruxes, but not like it
Dumbledore's character was always about saving others. He knew that if he didn't die, then Draco would die for failing his "master". so the choice was simple for dumbledore. I still think that when snape was hesitating, they were performing legilimancy on each other and arguing, when dumbledore just finished with speaking aloud "please" and then snape killed him to save draco. I think that draco/snape will end up being pivotal role in the destruction of voldemort. I do agree with ian1138, snape's anger was in having to kill the only man he's ever trusted and I really hope he gives voldemort a run for his money if they ever do fight in the book.
Harry will end up with Ginny, if he survives of course. I think that's pretty laid out for us. He has more or less become a member of that family anyway, so making it official wouldn't really change that much. Remus will die I think protecting harry, I mean he's a werewolf and what was the point of giving wormtail a SILVER hand if not to kill a werewolf with it.
He's one of my favorite characters, but he will bite the dust. I'm rambling on here, so no more...