Just finished reading Harry Potter books 1-6. Have #7 ordered and will probably read it on Sunday.
Not sure where things will go. There's a great blogpost somewhere that has given me some ideas, so what little is below is probably not of my own devising. Anyway, a few thoughts.
1) R.A.B. is Regulus Black.
2) The Hog's Head barman, Dumbledore's brother, has a role to play.
3) Harry is, himself, a Horcrux. I believe he's the one from Godric Gryffindor, because I believe he is descended from GG.
4) I had thought that HP would have to sacrifice himself (Jesus-like) to get rid of the Horcrux, but it's been made clear that the 7th bit of Voldemort's soul, the bit residing in his body, has to be destroyed last, so I don't see how that will work. But I do think Harry vanquishes V and dies in the process.
5) The International Relations/diplomacy angle will figure in, as both sides compete to form coalitions with the various other kinds of magical creatures.
Really neat books, good to read them all again.
Update: here's one of the posts I cribbed from.
And this one by Russell Arben Fox.