I'm almost speechless after reading this, as it's a fantastic retelling of the origin story, and really does manage to make the story vibrant and fresh again. I can't resist making comparisons with both Batman:Year One, and Christopher Nolan's Batman Begins as they both take a similarly 'realistic' take on the story and strangely Alfred even looks to my eyes, a little like Christian Bale in some panels. To me Batman :Earth One exceeds both of these as it reinvents the characters in some truly interesting ways and gives new insights to their motivations, while keeping the core identities intact. However, the real revelation came with Gary Frank's art, I've always liked his stuff, but never been completely blown away until now. Panel after panel, and page after page, is simply stunning. The book is filled with details, wonderfully characterful faces, and fantastically fluid action sequences. There are also some sly references towards characters we already know, including a wonderful sight gag, and some incredibly intricately detailed backgrounds, so every page becomes a delight.
The story itself goes to some surprisingly dark places, but left me wishing this was an ongoing title, as I would definitely love to see more of this version of the caped crusader.