1. The Confederate Approach on Harrisburg: The Gettysburg Campaign's Northernmost Reaches by Cooper H. Wingert (The History Pr, 2012).
As first glance, this is a very appealing book -- well illustrated, with good Heiser maps, and all indications are that it is thoroughly researched. This and Scott Mingus's Flames Beyond Gettysburg should form a nice pairing (Mingus wrote the foreword to Wingert's book). Among other things, Wingert covers the defensive preparations of Harrisburg, the fighting at Oyster Point and Sporting Hill, and the bombardment of Carlisle. While having gone no further than page flipping, I would venture that most Gettysburg students would want to grab a copy of this.
2. Confederate Incognito: The Civil War Reports of "Long Grabs," a.k.a. Murdoch John McSween, 26th and 35th North Carolina Infantry by Murdoch John McSween, edited by E.B. Munson (McFarland, 2012).
During the war, McSween wrote more than 80 letters to the Fayetteville Observer under the pen name "Long Grabs". His correspondence covers fighting in Virginia and North Carolina, as well as experiences training conscripts in his home state.
3. Colonel Edward E. Cross, New Hampshire Fighting Fifth: A Civil War Biography by Robert Grandchamp (McFarland, 2012).
Grandchamp, the author of several works of Rhode Island military history, here offers a biography of Edward Cross, who fought well in many great eastern theater battles before being mortally wounded at Gettysburg. It is a warts and all look at the man's life, with the book suggesting that he was an alcoholic with a combative personality off the battlefield, as well.