It's often hard to know exactly how reliable published information is - in particular if the publishing medium is the Internet. However, when the German chess book retailer Niggemann informs that Collins' book 'An Attacking Repertoire for Black' has been canceled, I assume they have a reliable source - most likely the publisher Batsford/Anova.
Although it came as no great surprise (see my blog entry of May 31), it's really a pity that the book probably never will materialize. It's a great title; a subject that's likely to interest a lot of club players; and it promised to discuss some really interesting subjects.
In particular I was eager to see Collins' ideas on the Stonewall versus 1.c4 and 1.Nf3. It would be a great selling point for a book on the Stonewall if it offered a complete answer to the Closed games. The subject hasn't received a lot of attention in sources that I have access to. Actually the only systematic treatment I could find was an old article in a Spanish language magazine and some analysis from White's point of view in Khalifman's 'Opening for White According to Kramnik'.
There of course still is the possibility that the book will appear by another publisher, but that would most likely delay the publishing date too much for me to include it as a reference for my upcoming Stonewall book.