http://www.evilhat.com/home/designers-dragons/You can download a 120 page free preview of this 4 book series, by Shannon Appelcline. Unlike many of the existing RPG history books, Appelcline apparently intends to focus on the 4 decades of RPG industry history, and less on the origins of RPGs, Wargaming etc.
As to Blackmoor, this author too insists on April 17th 1971 as the date of the first appearance of Blackmoor, although at least he does admit that there is discussion about the exact date. (Here at the CBI we know that original players in Arneson's group can confirm the date to the winter of 1970/71 for the first Blackmoor games. )
Accoring to this book, dungeon type adventuring, below Castle Blackmoor began in 1971. The book refers to the Castle as based on a Sicillian Model, which I believe is wrong, since clearly Branzoll Burg is found in the Tyroll region of northern Italy?
The book also mentions John Snider as one of the people running Blackmoor Campaigns. I know that Richard Snider was running Blackmoor, but did John do so as well? This preview of the book does not mention Richard in this context.
Obviously, the focus on the book is not really Arneson and the creation of D&D, nor the history of the Blackmoor Game. However, it is interesting to see how carefully one must step when making sure to get ones facts right in these aspects of gaming history.
In any case, this looks like its going to be an interesting series of books, with a lot of of useful information collected in one place. :)
-Havard