Snuff, the next Discworld book by Pratchett, will be released in the UK on the thirteenth of October, 2011. Two days before my sister's birthday. With luck it comes out in NZ at the same time, and I've got an easy birthday present ;D If not, then poor her, tis all MINE.
But it is confirmed. And the title is still listed officially as 'Snuff'. It's probably too early for overseas dates to be confirmed yet, but I think it's usually the same everywhere.