Information on ordering can be found here.
On Concordia's main page, there isn't any advertisement yet on this upcoming book (at least none that I could find!). Nor is this new volume featured prominently on their Luther page (yet). As a subscriber, I'm set up for automatic delivery which saves 30% off the price.
However, they do offer a lengthy pdf sample from this new volume that I came across quite by accident.
About this Volume:
This volume contains Luther’s prefaces to the works of others from 1532 to 1545. Amid the outpouring of print in the wake of the Reformation, Luther—especially in the prefaces to his own works—sometimes expressed the wish that his own books might disappear and give place to the Bible alone. In his prefaces to the works of others, however, Luther developed the opposite rhetorical strategy, hailing their books as faithful guides to the Scriptures or as edifices that, because of their confession of Christ, would “surely stand secure on the Rock upon which they are built.” Although he complained of the many “useless, harmful books” with which the Gospel’s opponents flooded the world, the multiplication of “good books” in print—of which there could never be too many—was a sign of God’s present blessing on the church in restoring the light of the Gospel, and Luther was pleased to encourage the works of faithful colleagues and friends. Many of the works for which he wrote prefaces he declared superior to his own for their insights, style, and more refined approach. Luther was grateful for help in the shared work of Evangelical literary production in all its genres, in constructive work as well as in polemics, and his prefaces give a broad survey of the Reformation’s literature.