I admit freely that I am excited about this book. I get a lot of joy out of nerd reference, and the Michael Fleisher Encyclopediae are already good resources for the Golden and early Silver Ages. However, it strikes me that, as currently described, the Greenberger book may well end up being a de facto DC encyclopedia. “Every Batman comic book appearance in the DC Universe” could conceivably include his adventures with the Justice League and Outsiders, to say nothing of the Robins’ involvement with the Titans and Young Justice, or even the Golden Age Batman’s adventures with the All-Star Squadron and Justice Society. The Fleisher volume had brief entries on the Elongated Man, Superman, and the Legion of Super-Heroes, based on those characters’ team-ups with Batman in Detective and World’s Finest.
However, by the same token, you’d think the new volume would have entries on everyone who’d guest-starred with Batman in The Brave and the Bold, plus most members of the Justice League, Justice Society, Marvel Family, New Gods, Checkmate, Suicide Squad, Teen Titans, New Titans, Birds of Prey, Young Justice, Challengers of the Unknown, Outsiders, Injustice League, Secret Society of Super-Villains, Fearsome Five … you get the idea.
Therefore, I can’t expect Greenberger’s book to be as comprehensive as the description might suggest, but realistically there’s no way it could be. It should still be a fun read, though, and a great resource for many years to come. Plus, you’d think all that research would make the inevitable Superman update that much easier.