Isn't this how it often happens...the Civil War community long laments the lack of a modern biography of a major Civil War figure, then suddenly three appear at roughly the same moment [well, in the publishing world's timetable, I consider within 18 months the 'same time'!].
Christopher J. Einolf had the good fortune to make it out of the gate first, with his well reviewed (but unfortunately still unread by me) Univ. of Oklahoma Press book George Thomas: Virginian for the Union(Nov. 2007).
Up next, by the first half of next year, we'll see:
Master of War: The Life of General George H. Thomas by Benson Bobrick (Simon & Schuster, Feb. 2009).
General George H. Thomas: A Biography of the Union’s “Rock of Chickamauga” by Robert P. Broadwater (McFarland, Spring/Summer 09).
Taking reviews of prior work into consideration, I don't hold out a great deal of hope for the last. I've never heard of Mr. Bobrick before, but a quick Amazon search comes up with quite a range of subjects (many well-received) from this very prolific author.