1. War's Desolating Scourge: The Union's Occupation of North Alabama by Joseph W. Danielson (UP of Kansas, 2012).
The Union's first military occupation of a large stretch of the Deep South with significant Confederate and unionist populations is always a fertile subject for study. A much admired favorite is Bradley and Dahlen's From Conciliation to Conquest.
2. Chasing Jeb Stuart and John Mosby: The Union Cavalry in Northern Virginia from Second Manassas to Gettysburg by Robert F. O'Neill (McFarland, 2012).
I seem to recall one or more Blue and Gray feature articles by O'Neill having to do with this subject. My initial impression is that this is a well researched operational and tactical history.
3. A History of the Negro Troops in the War of Rebellion, 1861-1865 by George Washington Williams (Fordham UP, 2012).
A paperback reprint of Williams's 1887 study, this new edition includes an introduction by John David Smith. The back cover bio credits Williams with authoring "the first work of serious scholarship by an African American" [1882's History of the Negro Race in America, 1619-1880] and Smith is interested in reassessing this later book's content and historiographical value.