I expect I shall buy my copy heavily discounted from my local Tescos at about teatime on the day it's released. Remarkably effective with no queues for the last two HPs.
Agree that Dumbledore is really dead, but that his portrait will come in handy.
Agree that Snape is a double agent, but am going to guess that *he* will be the one to actually kill Voldemort and be killed himself in the battle - I seem to recall HP being very depressed at the thought that he would either die or have to kill V in cold blood - perhaps JKR will save him from that moral dilemma. HP will be present though, having destroyed all the remaining Horcruxes, but will be held up by slow-on-the-uptake Malfoy while Snape races ahead, so say to 'warn' Voldemort but actually to dust him.
Ron & Hermione/Harry & Ginny - no brainer.
Perhaps I'm wrong and HP will die so JKR doesn't have to write about him any more - I'd be fairly bored with him if I were her (although all that cash must make up for it). But there would be such an outcry if she did kill him off (remember Conan Doyle having to bring back Sherlock Holmes?) - and think about the loss of future revenues (
): HP going to Wizard University, HP training to be an Auror and mopping up all Voldemort's supporters, HP suddenly realising that Voldemort was just the sidekick and the Most Ultimately Evil Wizard in the universe is actually Arthur Weasley, HP's children (hooray, more Hogwarts), etc.
The ewoks will turn out to be in disguise from an alternate universe, possibly the Dungeon Dimensions... sorry, I'm getting my authors mixed now too.