I'm talking about The Blackmar-Diemer Gambit: A modern guide to a fascinating chess opening, by Christoph Scheerer (previously Wisnewski). Back in September I noted that the publisher, Everyman Chess, had announced that the book would be out in October in the U.S., the following month in the E.U. Today the Everyman site has the months slipped to December and January. For a while Amazon U.S. said it was out of print (well, maybe so, if it had never been in print). Now Amazon lists it as available 31 Dec 2009.