This website says the stamp "will be available beginning November 23, 2017." Zenit provides this description of the stamp:
The postage stamp issued by the Philatelic Office for the occasion depicts in the foreground Jesus crucified and in the background a golden and timeless view of the city of Wittenberg. With a penitential disposition, kneeling respectively on the left and right of the cross, Martin Luther holds the Bible, source and destination of his doctrine, while Philipp Melanchthon, theologian and friend of Martin Luther, one of the main protagonists of the reform, holds in hand the Augsburg Confession (Confessio Augustana), the first official public presentation of the principles of Protestantism written by him.
What's interesting is that the Vatican also issued a stamp commemorating St. Francis de Sales, a person who actively attacked the Reformation. Zenit says, "He carried out his ministry with the firm desire to safeguard the Church of Rome from the reform of Calvin." Perhaps though in a few years the Vatican will release a John Calvin stamp.
I do feel sorry for many of Rome's defenders. A lot of them "converted" from Protestantism, and in their early zeal enjoyed throwing Luther and the Reformation under the bus. Now, their infallible church honors the memory of not only Luther, but Melanchthon as well. This demonstrates one of the blatant follies of the entire Roman Catholic apologetic enterprise. As a Protestant, there is no really eternal reason for "converting" to Rome. If Rome holds Luther and Melanchthon are penitent at the foot of the cross, then by extension other Protestants are as well.
No analogy is perfect. Rome's apologists remind me of downloading freeware. Sure, the freeware works, but if you want more options, you have to pay some fee to get the expanded version with more features. The goal of Rome's apologists is to convince you to get the upgrade. When I look at the extra options Rome provides, I'm not interested. If the basic version provides Jesus Christ, you can keep the expanded version that includes saints, purgatory, indulgences, papal infallibility, transubstantiation, monkery, Mary's immaculate conception and assumption, etc. No thank you.