Harry lives. It's a kids' book, folks. Same for Ron, Ginny, and Hermione.
The rest of the Weasleys I'm not so optimistic about. Percy is perfectly positioned to die as a result of trusting/ignoring Voldemort, to Show What Happens To Those Who Don't Pay Attention to the Heroes. The twins are expendable--they're Bad Boys, so killing them has some moral lessons involved. They do contribute some resources to the plot as gadgeteers, but you only need one of them for that. So I think we're going to lose one twin. Only the most die-hard fans will remember which one. The Weasley parents are also likely to go just because of the sheer angst it'd inflict on the main heroes.
For a bit of sheer speculation, note that Charlie's work with the dragons gets mentioned in just about every book. When Voldemort starts moving openly I could see Charlie leading a regiment of dragon cavalry to attack him. He'll lose, of course--too much of a deus ex machina to be a satisfying ending. At best he'll be the Aragorn, distracting Voldemort so Harry can sneak in and Save The Day.
Harry is not a Horcrux. Voldemort had to choose them in advance, and wanted them to be significant objects. An infant didn't qualify, and there was no way to tell he'd become famous before Voldemort lost the power to make them.
Snape prepares for his visits to Voldemort by placing incriminating memories in a Pensieve. Harry will find this and experience the memory of when Snape killed Dumbledore. This will be a very long conversation using Legilimency in which Dumbledore orders Snape to do it. This will probably happen right after Harry does some irrevocable nasty thing to Snape on the assumption that he's a traitor.
Snape will be crucial to the defeat of Voldemort.
Harry and Ginny will not be "a couple" during the course of the book. After a particularly crushing defeat, Ginny will restore Harry's morale and cause thousands of fans to slashdot the UK gov't age-of-consent-laws website. The happily-ever-after epilogue will have them together.