Behemoth by Scott Westerfeld will be released on October 5th, 2010 by Simon Pulse (Hardcover, illustrated, $18.99, 496 pages).
Let me explain the basic concept to you: World War I. The Allies have Darwinian genetically-engineered monsters for war engines and the Central Powers have mechas. Do you really need to read the rest of the review?
Oh, yeah, wait. One last thing before you rush off. This is the second book, the first is called Leviathan. Alright, go for it. Spoilers after the jump.