Yes, I too received such an email this morning. It is officially sold out. But as archetype noted, there is now a new project that is almost at completion called The Pinecaster Book. I probably can't really afford any of them, anyway -- especially now that those who have The Blackguard Book can really jack up the price! Oh well...
If you're on his list of folks who want the book, you'll eventually get an e-mail offering the book at a somewhat lower price. Being ex-book publishing, myself, I get the idea. Recoup your production costs early at a lower sales price, then sell the rest at the regular price.