I've had several people point me toward this thread over at the Troll Lord Games forums, where there would appear to be visual proof that the Castle Keepers Guide for Castles & Crusades actually exists. I know that's hard to believe, since the book has been delayed repeatedly since the middle of the last decade. I haven't seen a copy myself, so I can't provide any details about its length, contents, or quality, but I'm glad for C&C players that it's finally finished and available.
Mind you, this news doesn't mean a lot to me personally. My brief flirtation with Castles & Crusades was back in 2006, when I abandoned D&D III and started looking for an alternative. I still have fond feelings for C&C, since it was what helped me realize that what I really wanted was not a simplified 3e with some old school chrome but the real McCoy. That's why, in 2007, I turned to OD&D and wound up where I am today and I owe that to Castles & Crusades.
That probably doesn't sound like a compliment, but I sincerely mean it as such. C&C, even moreso than Third Edition, made me realize what I actually like about and want out of Dungeons & Dragons. Without it, I probably would have given up on D&D altogether.